Table Of Contents
Release Notes for the Cisco PIX Firewall Version 5.2(3)
Cisco IOS Software Interoperability
Cisco Secure Policy Manager Interoperability
Cisco Secure VPN Client Interoperability
Cisco VPN 3000 Concentrator Manager and Client Interoperability
PIX Firewall Manager Interoperability
Determining the Software Version
Upgrading to a New Software Release
New Information in Release 5.2(3)
New Information in Release 5.2(2)
New Hardware Features in Release 5.2(1)
Inside and Outside Port Restriction Change
New Software Features in Release 5.2
Certification Authority Servers—Baltimore and Microsoft
Cisco VPN 3000 Client (Formerly the Altiga VPN Client)
DHCP Server and Client Support
IP Fragmentation Syslog Messages
Unicast Reverse Path Forwarding
Websense Filtering by Username and Group
New Command Options in Version 5.2
Command Changes in Version 5.2
Removed Messages in Version 5.2
Cisco VPN 3000 Concentrator Manager
Token-based Authentication for VPN Clients
Resolved Caveats - Release 5.2(3)
Resolved Caveats - Release 5.2(2)
Resolved Caveats - Release 5.2(1)
Obtaining Technical Assistance
Obtaining Additional Publications and Information
Release Notes for the Cisco PIX Firewall Version 5.2(3)
October 2000
Contents
This document includes the following sections:
•
Obtaining Technical Assistance
•
Obtaining Additional Publications and Information
Note
Version 5.2(3) fixes caveat CSCds38708 only. If your configuration includes the fixup protocol smtp port_number command and either a conduit or access-list command statement permitting access to SMTP, you should install version 5.2(3) immediately to counter a vulnerability in the Mail Guard feature.
Introduction
The Cisco PIX Firewall provides secure networking and NAT (Network Address Translation).
System Requirements
The sections that follow list the system requirements for operating a Cisco PIX Firewall unit with version 5.2 software.
Memory Requirements
Note
All PIX Firewall units must have at least 32 MB of RAM memory or the PIX Firewall unit will not boot. In addition, all units except the PIX 506 must have 16 MB of Flash memory to boot. The PIX 506 has 8 MB of memory, which works correctly with version 5.2.
The following table lists Flash memory requirements for this release:
Software Requirements
The following is required for version 5.2:
1.
The PIX Firewall image no longer fits on a diskette. If you are using a PIX Firewall unit with a diskette drive, you need to download the Boothelper file, bh521.bin, from cisco.com to let you download the PIX Firewall image with TFTP.
2.
If you are upgrading from version 4 or earlier and want to use the IPSec or VPN features or commands, you must have an activation (license) key that enables Data Encryption Standard (DES) or the more secure 3DES.
To obtain a DES (56-bit) license key for the PIX Firewall, use the IPSec 56-bit Customer Registration form. Accessing this form requires prior registration on Cisco.com at http://tools.cisco.com/RPF/register/register.do. However, access to this form does not require a purchase or service contract. You can register as a guest and then proceed to fill out the form. The form is available at the following website:
http://www.cisco.com/pcgi-bin/Software/FormManager/formgenerator.pl?pid=221&fid=324
You must purchase a 3DES (168-bit) license key, or have a service contract, to obtain a 3DES license key. If you have already purchased a 3DES upgrade, and you have your Cisco PIX Firewall 3DES upgrade document with the entitlement number printed on it, you can register your license key for use on your PIX Firewall with the License Registration form. Accessing this form also requires prior registration on Cisco.com at http://tools.cisco.com/RPF/register/register.do. The License Registration form is available at the following website:
http://www.cisco.com/pcgi-bin/Software/FormManager/formgenerator.pl?pid=221&fid=301
You must also purchase or have a service contract to download PIX Firewall software.
3.
If you are using PFSS (PIX Firewall Syslog Server), Cisco recommends you install Windows NT Service Pack 6 to fix year 2000 conflicts in Windows NT.
4.
If you are upgrading from a previous PIX Firewall version, save your configuration and write down your activation key and serial number. Refer to "Installation Notes" for new installation requirements.
Cisco IOS Software Interoperability
If you use IKE Mode Config with the PIX Firewall, any routers on the IPSec connection must run Cisco IOS Release 12.0(6)T or later.
Cisco Secure Policy Manager Interoperability
Cisco Secure Policy Manager (Cisco Secure PM), version 2.1, provides policy-based management support for PIX Firewall units running version 4.2, 4.4, and 5.1 software images. Cisco Secure PM version 2.2 supports PIX Firewall version 5.2.
Refer to the documentation set for Cisco Secure PM at the following site:
http://www.cisco.com/en/US/products/sw/secursw/ps2133/prod_technical_documentation.html
Cisco Secure VPN Client Interoperability
PIX Firewall version 5.2 requires Cisco Secure VPN Client version 1.1. The Cisco Secure VPN Client can be used with Windows 95, Windows 98, and Windows NT version 4.0. The Cisco Secure VPN Client is not supported for use with Windows 2000.
Cisco VPN 3000 Concentrator Manager and Client Interoperability
PIX Firewall version 5.2 requires Cisco VPN 3000 Client version 2.5 or later and Cisco VPN 3000 Concentrator Manager version 2.5.2 or later. The Cisco VPN 3000 Client can be used with Windows 95, Windows 98, and Windows NT version 4.0. The Cisco VPN 3000 Client is not supported for use with Windows 2000.
PIX Firewall Manager Interoperability
You can use PIX Firewall version 5.2 with the PIX Firewall Manager version 4.3(2)f. Refer to the PIX Firewall Manager Release Notes, Version 4.3(2)f for more information. You can view this document online at the following site:
http://www.cisco.com/en/US/products/sw/secursw/ps2120/prod_release_note09186a008008c1d1.html
The PIX Firewall Manager (PFM) lets you manage PIX Firewall units; however, it does not let you configure any PIX Firewall features added after version 4.3(2).
The "Frequently Asked Questions" section in the PFM release notes provides useful troubleshooting information.
Determining the Software Version
Use the show version command to verify the software version of your PIX Firewall unit.
Upgrading to a New Software Release
If you have a cisco.com login, you can obtain software from the following site:
http://www.cisco.com/pcgi-bin/tablebuild.pl/pix
New and Changed Information
New Information in Release 5.2(3)
Version 5.2(3) fixes caveat CSCds38708 only. If your configuration includes the fixup protocol smtp port_number command and either a conduit or access-list command statement permitting access to SMTP, you should install version 5.2(3) immediately to counter a vulnerability in the Mail Guard feature.
New Information in Release 5.2(2)
Version 5.2(2) fixes caveats CSCds30699 and CSCdr91002 only.
New Hardware Features in Release 5.2(1)
PIX 525
The new PIX 525 model has the fastest performance and highest capacity of any of the PIX Firewall series.
The PIX 525 provides the following features:
Note
FDDI interfaces are not supported for use on the PIX 525 in version 5.2.
Failover Serial Connection
The failover serial connection has been increased from 9600 baud to 117,760 baud (115K). The maximum supported length for the failover serial cable is 6 feet.
Note
Use the failover cable that is shipped with the PIX Firewall unit. If you use a replacement cable, it must have the same specifications as the supplied cable (length, type, and pinouts).
Inside and Outside Port Restriction Change
With the 5.2 software release, there are no longer restrictions on having to use specific Ethernet ports as the inside and outside network ports. Any port, whether fixed or a PCI expansion port, and any interface type, FDDI, Token Ring, Fast Ethernet, or Gigabit Ethernet, can be assigned to be the inside or outside network port.
Use the following notes, restrictions, and instructions for configuring inside and outside network ports:
•
Any change to an interface can potentially affect many of the PIX Firewall commands. If you change an interface IP address or the security level, use the clear xlate command to purge connection data.
•
For the PIX 515 and PIX 525, you do not have to use ETHERNET 0 for the outside network port and ETHERNET 1 for the inside network port. Any of the fixed or expansion ports can be configured to be the inside or outside network ports.
•
The outside network port must still be set to security level 0 (zero) and the inside network port must still be set to security level 100.
•
This revision does not change the rules for port numbering. Refer to the Cisco PIX Firewall Installation and Configuration Guide, Version 5.2 for a description of how ports are numbered for the different PIX Firewall models.
•
For backward compatibility, the default configuration will still show Ethernet port 0 as the outside port and Ethernet port 1 as the inside port. Use the nameif command to identify which port (using unique port names) that you want to configure as the inside and outside ports. The following is syntax of the nameif command:
clear|no|show nameif hardware_if if_name security_levelThe following is an example of the default interface name information using the show nameif command:
nameif ethernet0 outside security0nameif ethernet1 inside security100nameif ethernet2 pix/intf2 security10nameif ethernet3 pix/intf3 security15nameif token-ring0 pix/intf4 security20nameif gb-ethernet0 pix/intf5 security25New Software Features in Release 5.2
The following features are new in version 5.2. Refer to the Cisco PIX Firewall Configuration Guide, Version 5.2 for information about each software feature. IPSec features are described in the new Cisco PIX Firewall IPSec User Guide, Version 5.2.
AAA access-list Support
The new match access_list_name option was added to the aaa command.
Broadcast Addresses
PIX Firewall no longer uses network addresses or broadcast addresses in static and global command statements when creating NAT xlate translations. Broadcast addresses are those addresses with the bit pattern of all ones, when the network mask is applied. Network addresses are those addresses with the bit pattern of all zeros, when the network mask is applied.
For example:
global 1 10.1.0.0-10.1.255.255 netmask 255.255.255.0With this command, the network addresses 10.1.0.0, 10.1.1.0, 10.1.2.0, and so forth through 10.1.255.0, are excluded. In addition, the broadcast addresses 10.1.0.255, 10.1.1.255, 10.1.2.255, and so forth through 10.1.255.255, are excluded.
Certification Authority Servers—Baltimore and Microsoft
In addition to supporting the Entrust and VeriSign certification authority (CA) servers, the PIX Firewall now also supports CA servers developed by Baltimore Technologies and Microsoft.
Cisco VPN 3000 Client (Formerly the Altiga VPN Client)
Remote access VPN users employing the Cisco VPN 3000 Client, version 2.5, can now securely access their private enterprise network through the PIX Firewall, version 5.2.
Note
Be sure to configure the IKE Mode Config prior to configuring support for the VPN 3000 Client. In configuring IKE Mode Config, specify that the VPN Client initiates the IKE Mode Config.
Note
The Cisco VPN 3000 Client does not support Windows 2000 use.
DHCP Server and Client Support
Failover Polling Time
The new failover poll seconds command lets you determine how long failover waits before sending special failover "hello" packets between the Primary and Standby units over all network interfaces and the failover cable. The default is 15 seconds. The minimum value is 3 seconds and the maximum is 15 seconds. Set to a lower value for Stateful Failover. With a faster poll time, PIX Firewall can detect failure and trigger failover faster. However, faster detection may cause unnecessary switchovers when the network is temporarily congested or a network card starts slowly.
FTP—Prevent Embedded Commands
The strict option to the fixup protocol ftp command prevents web browsers from sending embedded commands in FTP requests. Each FTP command must be acknowledged before a new command is allowed. Connections sending embedded commands are dropped. The strict option only lets an FTP server generate the 227 command and only lets an FTP client generate the PORT command. The 227 and PORT commands are checked to ensure they do not appear in an error string.
H.323 V2
H.323 is a suite of protocols defined by the International Telecommunication Union (ITU) for multimedia conferences over LANs. H.323 supports H.323 VoIP gateways and VoIP gatekeepers. H.323 version 2 adds the following functionality to the PIX Firewall:
•
Fast Connect or Fast Start Procedure for faster call setup
•
H.245 tunneling for resource conservation, call synchronization, and reduced set up time
ICMP Access Lists
Enable or disable pinging to an interface. With pinging disabled, the PIX Firewall cannot be detected on the network. The new icmp command implements this feature. This feature is also referred to as configurable proxy pinging.
IP Fragmentation Syslog Messages
Syslog messages PIX-4-209003, PIX-4-209004, and PIX-4-209005 have been added to disclose IP fragmentation attacks.
IDS Syslog Messages
Cisco Secure Intrusion Detection System (Cisco Secure IDS) is an IP-only feature that provides some level of flexibility for the user to customize the amount of traffic that needs to be audited and logged.
PAT Enhancements
The following PAT enhancements were added:
•
To specify PAT using the IP address at the interface, specify the interface keyword.
global [(int_name)] nat_id address | interface
The following example enables PAT using the IP address at the outside interface in global configuration mode:
ip address outside 192.150.49.1nat (inside) 1 0 0global (outside) 1 interfaceThe interface IP address used for PAT is the address associated with the interface when the xlate (translation slot) is created. This is important for configuring DHCP, allowing for the DHCP retrieved address to be used for PAT.
When PAT is enabled on an interface, there should be no loss of TCP, UDP, and ICMP services. These services allow for termination at the PIX Firewall unit's outside interface.
•
To track usage among different subnets, you can specify multiple PATs using the following supported configurations:
Mapping Different Internal Subnets to Different PAT Addresses
The following example maps hosts on the internal network 10.1.0.0/16 to global address 192.168.1.1 and hosts on the internal network10.1.1.1/16 to global address 209.165.200.225 in global configuration mode.
nat (inside) 1 10.1.0.0 255.255.255.0nat (inside) 2 10.1.1.1 255.255.255.0global (outside) 1 192.168.1.1 netmask 255.255.255.0global (outside) 2 209.165.200.225 netmask 255.255.255.224Backing Up PAT Addresses
The following example configures two port addresses for setting up PAT on hosts from the internal network 10.1.0.0/16 in global configuration mode.
nat (inside) 1 10.1.0.0 255.255.0.0global (outside) 1 209.165.200.225 netmask 255.255.255.224global (outside) 1 192.168.1.1 netmask 255.255.255.0With this configuration, address 192.168.1.1 will only be used when the port pool from address 209.165.200.225 is at maximum capacity.
ping Command Enhancement
The PIX Firewall ping command no longer requires an interface name. If an interface name is not specified, PIX Firewall checks the routing table to find the address you specify. You can specify an interface name to indicate through which interface the ICMP echo requests are sent.
Radius Authorization
PIX Firewall now allows a RADIUS server to send user group attributes to the PIX Firewall in the RADIUS authentication response message. Authorization is granted with the access-list command statement.
SIP Support
Session initiation protocol (SIP), as defined by the Internet Engineering Task Force (IETF), enables call handling sessions—particularly two-party audio conferences, or "calls." SIP works with Session Description Protocol (SDP) for call signaling. SDP specifies the ports for the media stream. Using SIP, the PIX Firewall can support any SIP Voice over IP (VoIP) gateways and VoIP proxy servers. SIP and SDP are defined in the following RFCs:
•
SIP: session initiation protocol, RFC 2543
•
SDP: Session Description Protocol, RFC 2327
SSH
SSH (Secure Shell) is an application running on top of a reliable transport layer, such as TCP/IP that provides strong authentication and encryption capabilities. PIX Firewall supports the SSH remote shell functionality as provided in SSH version 1. SSH version 1 also works with Cisco IOS software devices. Up to five SSH clients are allowed simultaneous access to the PIX Firewall console.
Note
You must generate an RSA key-pair for the PIX Firewall before clients can connect to the PIX Firewall console. To use SSH, your PIX Firewall must have a DES or 3DES activation key.
Note
SSH permits up to 100 characters in a username and up to 50 characters in a password.
Note
SSH and failover are not supported for use together in version 5.2.
Obtaining an SSH Client
The following sites let you download an SSH v1.x client. Because SSH version 1.x and version 2 are entirely different protocols and not compatible, be sure you download a client that supports SSH v1.x.
•
Windows 3.1, Windows CE, Windows 95, and Windows NT 4.0—first download the free Tera Term Pro SSH v1.x client from the following site:
http://hp.vector.co.jp/authors/VA002416/teraterm.html
Then add the SSH extension to Tera Term Pro, which is available at the following site:
http://www.zip.com.au/~roca/ttssh.html
•
Linux, Solaris, OpenBSD, AIX, IRIX, HP/UX, FreeBSD, and NetBSD—download the SSH v1.x client from the following site:
http://www.openssh.com
•
Macintosh (users outside the United States only)—download the Nifty Telnet 1.1 SSH client from the following site:
http://www.lysator.liu.se/~jonasw/freeware/niftyssh/
TCP Intercept
The TCP Intercept feature improves the embryonic connection handling of the PIX Firewall. When the number of embryonic connections exceed the configured threshold, PIX Firewall intercepts and proxies new connections. Previous to version 5.2, PIX Firewall did not allow new connections after the embryonic connection threshold was exceeded.
This feature requires no change to the PIX Firewall command set, only that the embryonic connection limit on the static command now has a new behavior.
Unicast Reverse Path Forwarding
Unicast Reverse Path Forwarding requires that a source IP address is reachable via the receiving interface. This feature provides ingress and egress spoof filtering on the PIX Firewall. For more information, refer to RFC 2267. You can view this RFC at the following site:
http://www.cis.ohio-state.edu/htbin/rfc/rfc2267.html
Websense Filtering by Username and Group
The Websense Server works with the PIX Firewall to deny users from access to web sites based on the company security policy.
Websense protocol version 4 enables group and username authentication between a host and a PIX Firewall. The PIX Firewall performs a username lookup, and then the Websense server handles URL filtering and username logging.
Websense protocol version 4 contains the following enhancements:
•
URL filtering allows the PIX Firewall to check outgoing URL requests against the policy defined on the Websense server.
•
Username logging tracks username, group, and domain name on the Websense server.
•
Username lookup enables the PIX Firewall to use the user authentication table to map the host's IP address to the username.
Command Changes
All new commands, options, and changes are described in the Cisco PIX Firewall Configuration Guide, Version 5.2.
New Commands in Version 5.2
The following commands are new in version 5.2:
•
dhcpd—Enables the DHCP server feature on a specified PIX Firewall interface allowing the PIX Firewall to function as a DHCP server that provides network configuration parameters to DHCP clients.
•
flashfs—Prepares Flash memory for downgrade to previous PIX Firewall version.
•
icmp—Enables or disables pinging a PIX Firewall interface.
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ip audit—Configures use of Cisco Secure Intrusion Detection System signatures.
•
ip verify reverse-path—Implements Unicast Reverse Path Forwarding, also known as reverse route lookups.
•
ssh—Specifies the host or network authorized to initiate an SSH connection to the PIX Firewall.
•
vpngroup—Configures a Cisco VPN 3000 Client policy group. Refer to the Cisco PIX Firewall IPSec User Guide, Version 5.2 for more information.
New Command Options in Version 5.2
The following command options are new in version 5.2:
•
aaa accounting command, match access-list option—Provides AAA access list support.
•
aaa authentication command, match access-list option—Provides AAA access list support.
•
aaa authentication command, ssh console option—Specifies the group of AAA servers to be used for SSH user authentication.
•
aaa authorization command, match access-list option—Provides AAA access list support.
•
ca crl command, no option—Deletes the CRL within the PIX Firewall.
•
ca zeroize command, keypair_name option—Deletes a specific RSA key pair.
•
clear flashfs command, downgrade 4.x | 5.0 | 5.1 options—Prepares a Flash memory device for use by a previous PIX Firewall software version. Use the clear flashfs command before downgrading the PIX Firewall software to versions prior to 5.n. Otherwise, the Flash memory file system will get out of sync with the actual contents on the Flash memory device and cause problems when the unit is reupgraded.
•
debug command, dhcpc packet|detail|error options—Displays detailed information about the DHCP lease.
•
debug command, dhcpd packet|event options—Displays information about the DHCP server input/output (I/O) packets.
•
debug command—The debug packet command sends its output to the Trace Channel. All other debug commands do not. Use of Trace Channel changes the way you can view output on your screen during a PIX Firewall console or Telnet session.
If a debug command does not use Trace Channel, each session operates independently, which means any commands started in the session only appear in the session. By default, a session not using Trace Channel has output disabled by default.
•
failover command, poll seconds option—Lets you determine how long failover waits before sending special failover "hello" packets between the Primary and Standby units over all network interfaces and the failover cable.
•
fixup protocol ftp command, [strict] option—Prevents web browsers from sending embedded commands in FTP requests.
•
fixup protocol command, sip option—Enables SIP on an interface.
•
global command, interface option—Specifies that Port Address Translation (PAT) use the IP address of the PIX Firewall interface.
•
ip address command, dhcp [setroute] option—Instructs the PIX Firewall to configure the interface IP address and subnet mask through the DHCP. The optional setroute argument tells the PIX Firewall to set the default route using the default gateway parameter the DHCP server returns.
•
logging command, standby option—Let the failover Standby unit also send syslog messages. This option is disabled by default. You can enable it to ensure that the Standby unit's syslog messages stay synchronized should failover occur. However, this option causes twice as much traffic on the syslog server. Disable with the no logging standby command.
•
show ca command, crl option—Displays Certificate Revocation List (CRL) information from a given CA or LDAP server, such as the CRL issuer name, the date of the last CRL update, and the date of the next CRL update.
•
show conn command, state sip option—Displays all active SIP connections.
•
sysopt command, route dnat option—Specifies that when an incoming packet does a route lookup, the incoming interface is used to determine which interface the packet should go to, and which is the next hop.
•
sysopt command, uauth allow http-cache option—Allows the web browser to supply a username and password from its cache for AAA authentication.
•
timeout command, sip option—Modifies duration for sip inactivity timer. When this time elapses, the port used by the SIP service closes.
•
timeout command, sip media option—Modifies duration for sip_media inactivity timer. When this time elapses, SIP connections with RTP/RTCP expire.
•
url-server command, protocol TCP|UDP version 1|4 options—With version 4 option, performs a username lookup, and then the Websense server handles URL filtering and username logging. With the version 1 option, works the same as in previous PIX Firewall versions.
Command Changes in Version 5.2
•
access-list—Lets you specify an access list ID shared with an AAA server that provides RADIUS authorization. An access-group command statement is not used with this type of access list.
•
aaa-server—Up to 14 AAA servers are permitted.
•
filter url—This command accepts a port specification as shown in the following command syntax:
filter url port|except local_ip local_mask foreign_ip foreign_mask [allow]
The port option was available in past versions but did not appear in the documentation.
•
global—Lets you have multiple PATs. Also, PIX Firewall no longer uses network addresses or broadcast addresses in static and global command statements when creating NAT xlate translations.
•
ip local pool—When a pool of addresses set by the ip local pool command is empty, the following syslog message now appears:
%PIX-4-404101: ISAKMP: Failed to allocate address for client from pool poolname•
outbound—The java option is no longer supported.
•
outbound—The maximum list_ID value is 1599. You can now have up to 14,000 outbound command statements in a configuration.
•
ping—The interface parameter is now optional. If an interface name is not specified, PIX Firewall checks the routing table to find the address you specify.
•
show config—ISAKMP keys now appear as follows:
isakmp key ******** address ip_addr netmask mask•
show version—The serial number listed with the show version command in version 5.2 and later is for the Flash memory BIOS. This number is different from the serial number on the chassis. When you get a software upgrade, you will need the serial number that appears in the show version command, not the chassis number.
•
static—PIX Firewall no longer uses network addresses or broadcast addresses in static and global command statements when creating NAT xlate translations.
•
static—With the new TCP intercept feature, once the optional embryonic connection limit is reached, and until the embryonic connection count falls below this threshold, every SYN segment bound for the affected server is intercepted. For each SYN segment, PIX Firewall responds on behalf of the server with an empty SYN/ACK segment. PIX Firewall retains pertinent state information, drops the packet, and waits for the client's acknowledgement.
•
write terminal—ISAKMP keys now appear as follows:
isakmp key ******** address ip_addr netmask maskSyslog Message Changes
The sections that follow list changes to syslog messages in version 5.2. All messages are described in detail in Cisco PIX Firewall System Log Messages, Version 5.2.
New Messages in Version 5.2
The following syslog messages are new in version 5.2:
%PIX-2-106017: Deny IP due to Land Attack from IP_addr to IP_addr%PIX-1-106021: Deny num reverse path check from IP_addr to IP_addr on interface int_name%PIX-1-106022: Deny num connection spoof from IP_addr to IP_addr on interface int_name%PIX-6-109015: Authorization denied (acl=acl_ID) for user 'username' from src_addr/src_port to dest_addr/dest_port on interface int_name%PIX-3-109016: Downloaded authorization access-list acl_ID not found for user 'username'%PIX-4-209003: Fragment database limit of num exceeded: src = IP_addr, dest = IP_addr, proto = protocol, id = id%PIX-4-209004: Invalid IP fragment, size = num exceeds maximum size = size: src = IP_addr, dest = IP_addr, proto = protocol, id = id%PIX-4-209005: Discard IP fragment set with more than num elements: src = IP_addr, dest = IP_addr, proto = protocol, id = id%PIX-3-313001: Denied ICMP type=type, code=code from IP_addr on interface int_name%PIX-6-314001: Pre-allocate RTSP UDP backconnection for faddr faddr/fport to laddr laddr/lport%PIX-3-315001: Denied SSH session from IP_addr on interface int_name%PIX-6-315002: Permitted SSH session from IP_addr on interface int_name for user "user_id"%PIX-6-315003: SSH login session failed from IP_addr on (num attempts) on interface int_name by user "user_id"%PIX-3-315004: Fail to establish SSH session because PIX RSA host key retrieval failed.%PIX-6-315011: SSH session from IP_addr on interface int_name for user "user_id" terminated normally%PIX-6-315011: SSH session from IP_addr on interface int_name for user "user_id" disconnected by SSH server, reason: "text" (status_code_in_hex)%PIX-4-4000nn: IDS:sig_num sig_msg from IP_addr to IP_addr on interface int_name%PIX-4-404101: ISAKMP: Failed to allocate address for client from pool pool_idsha%PIX-4-405101: Unable to Pre-allocate H225 Call Signalling Connection for faddr faddr[/fport] to laddr laddr[/lport]%PIX-4-405102: Unable to Pre-allocate H245 Connection for faddr faddr[/fport] to laddr laddr[/lport]%PIX-6-604101: DHCP client interface int_name: Allocated ip = IP_addr, mask = mask, gw = IP_addr%PIX-6-604102: DHCP client interface int_name: address released%PIX-6-604103: DHCP daemon interface int_name: address granted MAC_addr (IP_addr)%PIX-6-604104: DHCP daemon interface int_name: address released MAC_addr (IP_addr)Removed Messages in Version 5.2
The following syslog messages were removed in version 5.2:
%PIX-2-106003: Connection denied src laddr dest faddr due to JAVA Applet on interface int_name.%PIX-3-201007: Unable to allocate new udp connections (faddr/fport-laddr/lport)%PIX-3-203001: ESP Error: No Key SPI hex SRC IP_addr DEST IP_addrDocumentation Changes
All IPSec configuration information is now in the Cisco PIX Firewall IPSec User Guide, Version 5.2. This guide is available both online and in the PIX Firewall accessory kit.
Installation Notes
Always configure a default route command statement to the outside interface in every configuration you create. This is especially important for use with IPSec.
Limitations and Restrictions
No new limitations or restrictions were added in version 5.2.
Important Notes
AAA
The inbound and outbound options to the aaa command apply only to the network interfaces in the first two slots of the PIX Firewall.
CRLs
When CRL checking is configured as mandatory, PIX Firewall takes about two minutes to poll the CRL from the VeriSign CA Server during ISAKMP negotiation. As a result, ISAKMP negotiation fails with the message "ISAKMP (0): Unknown error in cert validation, 0" and packets are lost until PIX Firewall receives the CRL. [CSCdr89880]
Cisco Secure VPN Client
•
The PIX Firewall now supports the E-mail Address ID Type used to identify the Cisco Secure VPN Client's peer. The ID Type is configurable within the Security Policy Editor, under My Identity. The E-mail Address ID Type is only applicable if you are using digital certificates.
•
PIX Firewall behaves differently when used with and without Xauth in combination with IKE Mode Config.
The problem occurs when IKE Mode Config is configured and PIX Firewall runs out of addresses created by the ip local pool command and the next VPN Client tries to come in.
The behavior is as follows:
–
Without Xauth configured—PIX Firewall lets the new VPN Client come in and sets up the tunnel with its own internal address.
–
With Xauth configured—PIX Firewall denies the new VPN Client due to lack of a local address, even if the VPN Client wants to use its own internal address.
This caveat does not exist for the Cisco VPN 3000 Client version 2.5. [CSCdr48442]
Cisco VPN 3000 Client
The following restrictions apply to using PIX Firewall with the Cisco VPN 3000 Client:
•
The esp-des and esp-3des transform sets do not work without esp-md5 and esp-sha. [CSCdr62289]
•
The Cisco VPN 3000 Client does not support AH protocol.
•
Only aggressive mode is supported.
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Cisco VPN 3000 Client has to use split tunneling to connect to a remote PIX Firewall unit if the Cisco VPN 3000 Client is going to browse through the private network on the inside of the remote PIX Firewall unit, as well as the local network of the Cisco VPN 3000 Client. [CSCdr74154]
•
From within the status window while a tunnel is available, if you press the Space key twice, the client hangs. [CSCdr74915]
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The Cisco VPN 3000 Client requires IKE Mode Config.
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The Cisco VPN 3000 Client does not support Group 2 for IKE transform sets. [CSCdr75514]
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When PIX Firewall creates multiple IPSec SPIs (security parameter indexes), the Cisco VPN 3000 Client uses the latest SPI to send data, but PIX Firewall does not. PIX Firewall does not keep track of the SPIs in the order they were created. PIX Firewall uses the SPI with the highest lifetime, but the latest SPI ends up with less lifetime than the one before.
For example, if you ping from the client and check the inbound and outbound SPIs, Cisco VPN 3000 Client can be seen to use the third (latest) SPI to send the ping, but PIX Firewall uses the second SPI, the one before the last, to respond to the ping. The result is that the ping responses return to the Cisco VPN 3000 Client, but are dropped. [CSCdr83223]
•
The Cisco VPN 3000 Client on Windows 95 or Windows 98 does not take the WINS server address pushed to it from the PIX Firewall if an IP address is statically configured on the client. For static configurations, users must manually configure the adapters with WINS information. This works correctly on Cisco VPN 3000 Client on Windows NT. On Windows 95 or Windows 98, dynamic WINS support works with DHCP enabled adapters; that is, PPP or NIC adapters that get their information dynamically. [CSCdr94941]
•
On PIX Firewall, you can configure multiple vpngroup command statements when using certificates with the Cisco VPN 3000 Client. This can be done only when the name of the vpngroup command statements you specify on the PIX Firewall is the same as the Organizational Unit (OU) field of the certificate on the client. When PIX Firewall is processing the client's certificate, it uses the value of the OU field of the certificate to associate with the vpngroup command statement and uses that. [CSCdr91010]
Cisco VPN 3000 Concentrator Manager
The following restrictions apply to use with the Cisco VPN 3000 Concentrator Manager series:
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The Cisco VPN 3000 Concentrator Manager rekeys every time an ISAKMP SA times out, which creates multiple SPIs on a PIX Firewall. [CSCdr74737]
•
The AH protocol is not supported.
•
Keepalive is not supported between PIX Firewall and Cisco VPN 3000 Concentrator Manager. Keepalive is not a standard. Currently, each vendor has their own definition for keepalives and what it is supposed to accomplish. PIX Firewall keepalives currently work only with other PIX Firewall unit's and Cisco IOS software routers. [CSCdr75726]
•
If IPSec traffic is not present between a PIX Firewall to a PIX Firewall, when the IPSec and ISA lifetimes expire, both IPSec and ISA SAs are deleted. If IPSec traffic is not present between a PIX Firewall and a Cisco VPN 3000 Concentrator Manager, when the lifetimes expire, the SAs are not deleted and the units rekey. [CSCds0487]
Failover
Refer to the "Failover" section in Chapter 3, "Advanced Configurations" in the Cisco PIX Firewall Configuration Guide, Version 5.2 for a new procedure for configuring failover.
The PIX Firewall DHCP client does not support failover configurations.
FDDI
FDDI interfaces are supported on the PIX 525 with the caveat that no other interface card can be used with FDDI cards. In addition, the Ethernet interfaces on the motherboard must be shut down using the shutdown option to the interface command.
On the PIX 520 and earlier models, when FDDI interface cards are used, no other interface card can be used on the unit.
The PIX 515 does not support use of any FDDI interface cards.
License Key Downgrade
If you downgrade your license key from a UR to an R, thereby restricting the number of supported interfaces, PIX Firewall removes all commands from your configuration that reference the unsupported interfaces. In addition, open caveat CSCdr52181 notes that PIX Firewall also removes all nat and static commands from the configuration.
SMTP
Multiple SMTP commands contained in a single packet are no longer permitted and are now dropped.
Token-based Authentication for VPN Clients
The PIX Firewall now supports token-based authentication systems through the use of the crypto map token authentication command. PIX Firewall supports the following token-based authentication systems and modes for use with the Cisco VPN 3000 Client:
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Security Dynamics (SDI) SecurID/ACE Server with SDI RADIUS
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Next Token mode
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New Pin mode
•
SDI with CiscoSecure ACS, NT version
–
Next Token mode
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New Pin mode
•
SDI with CiscoSecure ACS, UNIX version
–
Next Token mode
The PIX Firewall supports the SDI RADIUS token-based authentication system using Next Token mode or New Pin mode for use with the Cisco Secure VPN Client, version 1.1.
Token based authentication has not been verified for the following vendors/products:
•
CRYPTOCard
•
SafeWord
•
AXENT
For more information about the crypto map token authentication command, see the crypto map command page in Chapter 12, "Command Reference" of the Cisco PIX Firewall IPSec User Guide, Version 5.2.
Caveats
Note
Use Troubleshooting Tools on cisco.comcisco.com to view additional caveat information. You can access this tool at the following site:
http://www.cisco.com/public/support/tac/tools_trouble.shtml
Open Caveats - Release 5.2
•
CSCds26054
SSH and failover are not supported for use together in version 5.2. If used together, an RSA key created before failover will not appear on the Standby unit after failover occurs.
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CSCds10228
PIX Firewall is not able to create an IPSec tunnel with a 2048 RSA key using a PIX Firewall "Classic" model.
•
CSCds10022
PIX Firewall fails to get certificates if downgraded from 5.2 when used with the Microsoft Certification Authority.
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CSCds08487
When IPSec traffic is not present between a PIX Firewall to a PIX Firewall, when the IPSec and ISA lifetimes expire, both IPSec and ISA SAs are deleted. When IPSec traffic is not present between a PIX Firewall and a Cisco VPN 3000 Concentrator, when the lifetimes expire, the SAs are not deleted and the units rekey.
•
CSCdr96232
H.323 call setup is not supported by failover.
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CSCdr94941
The Cisco VPN 3000 Client on Windows 95 or Windows 98 does not take the WINS server address pushed to it from the PIX Firewall if an IP address is statically configured on the client. For static configurations, users must manually configure the adapters with WINS information. This works correctly on Cisco VPN 3000 Client on Windows NT. On Windows 95 or Windows 98, dynamic WINS support works with DHCP enabled adapters; that is, PPP or NIC adapters that get their information dynamically.
•
CSCdr96486
Always configure a default route command statement to the outside interface in every configuration you create. This is especially important for use with IPSec.
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CSCdr94034
ICMP types 3, 4, 5, 11, 12, 13, 14, 15, 16, 17, and 18 fail with PAT.
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CSCdr91340
During the PIX Firewall unit's enrollment request to a Baltimore CA server, the process fails. This failure occurs when using the ca enroll command to obtain CA-signed certificates for each of the two special-purpose RSA key pairs the PIX Firewall generated (using the ca generate rsa specialkey command). When the failure occurs, PIX Firewall displays the following error messages:
CRYPTO_PKI: status = 100: certificate is grantedCRYPTO_PKI: Error: Invalid format for BER encoding while##########In GetRecipientInfo: 315CRYPTO_PKI: status = 266: failed to open the envelopeThe certificate enrollment request failed!•
CSCdr89880
When CRL checking is configured as mandatory, PIX Firewall takes about two minutes to poll the CRL from the VeriSign CA Server during ISAKMP negotiation. As a result, ISAKMP negotiation fails with the message "ISAKMP (0): Unknown error in cert validation, 0" and packets are lost until PIX Firewall receives the CRL.
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CSCdr87814
SSH permits up to 100 characters in a username and up to 50 characters in a password.
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CSCdr83223
When PIX Firewall creates multiple IPSec SPIs (security parameter indexes), the Cisco VPN 3000 Client uses the latest SPI to send data, but PIX Firewall does not. PIX Firewall does not keep track of the SPIs in the order they were created. PIX Firewall uses the SPI with the highest lifetime, but the latest SPI ends up with less lifetime than the one before.
For example, if you ping from the client and check the inbound and outbound SPIs, Cisco VPN 3000 Client can be seen to use the third (latest) SPI to send the ping, but PIX Firewall uses the second SPI, the one before last, to respond to the ping. The result is that the ping responses return to the Cisco VPN 3000 Client, but are dropped.
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CSCdr83132
In version 5.1 and prior versions, when you enabled the debug command, output messages displayed at an active terminal session, such as the console or a Telnet session.
In version 5.2 and future versions, PIX Firewall supports multiple console sessions, which means that debug command output messages can be sent to multiple sessions simultaneously, as long as the sessions are enabled. Each session is enabled or disabled independently and there is no effect on other sessions.
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CSCdr75726
The Cisco VPN 3000 Concentrator Manager series ignores all keepalive messages originating from the PIX Firewall unit.
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CSCdr75706
PIX Firewall/Cisco VPN 3000 Concentrator Manager: traffic does not restart after power cycling the concentrator.
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CSCdr75514
The Cisco VPN 3000 Client does not support Group 2 for IKE transform sets.
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CSCdr74915
From within the Cisco VPN 3000 Client status window, while a tunnel is available, if you press the Space key twice, the client hangs.
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CSCdr74780
Use of the SNMP ip.ipAddrTable entry requires that all interfaces have unique addresses. If interfaces have not been assigned IP addresses, by default, their IP addresses are all set to 127.0.0.1. Having duplicate IP addresses causes the SNMP management station to loop indefinitely. The workaround is to assign each interface a different address. For example, you can set one address to 127.0.0.1, another to 127.0.0.2, and so on.
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CSCdr74760
When starting a SSH session, a dot (.) displays on the PIX Firewall console before the SSH user authentication prompt appears.
The dot appears as follows:
pixfirewall(config)# .pixfirewall(config)# .The display of the dot does not affect the functionality of SSH. The dot appears on at the console when generating a server key or when decrypting a message using private keys during SSH key exchange, before user authentication occurs. These tasks can take up to two minutes or longer. The dot is a progress indicator that verifies that the PIX Firewall is busy and has not hung.
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CSCdr74154
Cisco VPN 3000 Client has to use split tunneling to connect to a remote PIX Firewall unit if the Cisco VPN 3000 Client is going to browse through the private network on the inside of the remote PIX Firewall unit, as well as the local network of the Cisco VPN 3000 Client.
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CSCdr72486
In version 5.2, when keys and certificates generated with the crloptional parameter to the ca command are replaced with new ones, ISAKMP negotiation fails. This caveat previously worked correctly in version 5.1. This caveat was observed after creating keys and certificates, sending traffic, and removing the keys and certificates on both PIX Firewall units. After new keys and certificates were created with the crloptional parameter to the ca command and new traffic started, ISAKMP negotiations failed.
•
CSCdr71094
An ip local pool range cannot have multiple subnets.
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CSCdr68251
Port numbers are not appearing in syslog when using ACL.
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CSCdr66093
If PIX Firewall crashes, it attempts to run the show tech-support command. A long configuration can cause further crashes.
•
CSCdr64494
PIX Firewall using RADIUS or TACACS+ requires username and password pairs for authentication, but only authorizes based on IP addresses. Once a multiuser host has been authenticated, all other users on that host are granted authentication. This may allow unauthorized users access to services normally denied them.
Setting the uauth timeout to zero partially solves this problem, but makes Web browsing difficult for authorized users because they must reauthenticate for every new page they view.
•
CSCdr62289
The Cisco VPN 3000 Concentrator Manager, only supports a limited number of IPSec transform sets. The Cisco VPN 3000 Concentrator Manager does not support the AH protocol. The supported transform sets are as follows:
esp-des esp-md5-hmacesp-des esp-sha-hmacesp-3des esp-md5-hmacesp-3des esp-sha-hmacesp-null esp-md5-hmac•
CSCdr52181
If you downgrade your license key from a UR to an R, thereby restricting the number of supported interfaces, PIX Firewall removes all commands from your configuration that reference the unsupported interfaces. In addition, PIX Firewall also removes all nat and static commands from the configuration.
•
CSCdr48442
PIX Firewall behaves differently when used with and without Xauth in combination with IKE Mode Config when used with the Cisco Secure VPN Client. Refer to the second bullet item in "Cisco Secure VPN Client" for more information.
•
CSCdr43729
The aaa authorization except command does not work for UDP.
•
CSCdr33945
Crash in Crypto PKI RECV thread during certificate enrollment.
•
CSCdr15304
The following syslog message incorrectly displays a field as "<>":
%PIX-3-106014: Deny inbound icmp src outside:IP_addr dst <>:IP_addr (type 0, code 0)
•
CSCdr04004
Small ARP timeouts cause short periods of packet loss.
•
CSCdp60588
Interface routing should be based on the DNAT address.
•
CSCdp55755
Outbound filtering is not working correctly. An example is as follows:
outbound 2 permit 0.0.0.0 0.0.0.0 0 tcpoutbound 2 deny 192.168.85.51 255.255.255.255 0 ipoutbound 2 deny 192.168.85.51 255.255.255.255 0 tcpapply (inside) 2 outgoing_srcIf you do not have the third command statement, the second line does not stop TCP packets. It may sound logical, the protocol values may be UDP, TCP, or the ICMP protocols. In this case, ip is not a valid protocol, and thus, not evaluated by the PIX Firewall, but it is not denied by PIX Firewall command line parser.
Resolved Caveats - Release 5.2(3)
•
CSCds38708
The fixup protocol smtp command no longer permits commands it would normally screen out from being appended to the SMTP DATA command.
Resolved Caveats - Release 5.2(2)
•
CSCds30699
PIX Firewall continues to filter SMTP commands if the DATA command fails. Previously, the Mail Guard feature would stop filtering if the DATA command failed. The Mail Guard feature is enabled with the fixup protocol smtp port_number command, which is enabled in the PIX Firewall unit's default configuration.
•
CSCdr91002
Multiple SMTP commands contained in a single packet are no longer permitted and are now dropped.
Resolved Caveats - Release 5.2(1)
The following caveats were resolved:
•
CSCds08316
H.323 now correctly performs NAT on IP addresses configured with the alias command.
•
CSCds02965
The fixup protocol rtsp command no longer allocates the wrong server port for QuickTime.
•
CSCdr97777
When using the fixup protocol ftp strict command, FTP communications between a server that advertises a big welcome banner, and a Windows 2000 or Netscape Communicator 4.73 client now works correctly.
Previously, these types of FTP connections were treated as intrusion events and dropped. The problem occurred because these clients issued the next command before receiving the complete advertised banner from the server. PIX Firewall treated this as a pipelined command, which with the strict option, is treated as an intrusion event.
•
CSCdr96658
PIX Firewall no longer crashes during Cisco Secure PM configuration downloads.
•
CSCdr96442
All inside interface static route command statements now appear in the configuration. Previously, an RIP-generated route overrode the static route and kept it from appearing in the configuration. Now the static route overrides an RIP-generated route.
•
CSCdr93006
PIX Firewall no longer creates two PPTP tunnels for the same client.
•
CSCdr92704
The configure net command no longer changes the severity level of the logging history command.
•
CSCdr91940
Failover with an Ethernet cross-over cable no longer causes the configuration in the Standby unit to be lost and the network to become temporarily unavailable.
•
CSCdr91608
PIX Firewall now verifies that an xlate is linked to a host object; if not, the "no local host infor" message appears when the show xlate debug command is used. Previously, Telnet sessions were being lost during Stateful Failover.
•
CSCdr91205
Creates the sysopt route dnat command, which specifies that when an incoming packet does a route lookup, the incoming interface is used to determine which interface the packet should go to and what is the next hop.
•
CSCdr91010
On PIX Firewall, you can configure multiple vpngroup command statements when using certificates with the Cisco VPN 3000 Client. This can be done only when the name of the vpngroup command statement you specify on the PIX Firewall is the same as the Organizational Unit (OU) field of the certificate on the client. When PIX Firewall is processing the client's certificate, it uses the value of the OU field of the certificate to associate with the vpngroup command statement and uses that.
•
CSCdr91002
Multiple SMTP commands contained in a single packet are no longer permitted and are now dropped.
•
CSCdr90259
Uauth now shows the correct address specified by the ip local pool command when doing xauth with a VPN Client. Previously, this problem noted that ISP assigned address appeared instead of the correct pool address.
•
CSCdr90153 and CSCdr87363
Stateful Failover now supports the nat 0 access-list command.
•
CSCdr88834
Specifying an outbound command list_ID greater than 1599 no longer causes a crash. The maximum list_ID value is now 1599.
•
CSCdr83692
The write standby command now clears the configuration of the Secondary unit and its ARP table. The Active unit then sends each configuration command to the Secondary unit. While sending the commands to synchronize the two configurations, the failover IP addresses are now temporarily disabled (set to 0.0.0.0), which prevents the previous condition that when syslog was enabled, the Secondary unit would ARP for the syslog server and cause confusion on the network.
•
CSCdr81757
PIX Firewall now polls the CRL during ISAKMP negotiation to determine if the CRL has expired.
•
CSCdr81437
The embryonic connection count no longer underflows during Stateful Failover.
•
CSCdr80161
The inbound and outbound options to the aaa command are restricted to first and second interfaces only.
•
CSCdr78688
PIX Firewall now supports up to 14,000 outbound command statements in a configuration.
•
CSCdr75864
Syslog message PIX-5-304001 now displays a username. The format of this message is as follows:
%PIX-5-304001: user src_addr Accessed JAVA URL|URL dest_addr: url.•
CSCdr73112
The tracert command now displays hops beyond the PIX Firewall when using PAT.
•
CSCdr69366
PIX Firewall no longer incorrectly NATs embedded IP addresses with a network static command statement.
•
CSCdr69195
PIX Firewall no longer fails with an assertion error when 50 or more IPSec static peers are configured. In this case, each peer was configured with individual ISAMKP keys, ISAKMP policies, transform sets, and lines to match address access-lists.
•
CSCdr69061
SIP uses three signaling ports, which caused problems for SIP UDP signaling. SIP can also use TCP, but the problems and solutions only apply to UDP signaling. Normally, SIP with UDP has a configurable timer set by default to 30 minutes. This caused the database and signaling connections to remain until this timer expired.
A new timer and flag were added for transient connections, so that a connection will now time out and be closed in 1 minute when the media ports are assigned and connections are made either in the 183 ringing message or the 200 OK response message.
The call is then moved to the active state and the connection address is saved in the database at this time. When the terminating message arrives on a different connection, the active connection address will be retrieved from the database and the UDP flag will be changed on this connection to the transient flag.
•

