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Cisco IOS XR IP Addresses and Services Command Reference, Release 3.7
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Preface
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Access List Commands on Cisco IOS XR Software
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ARP Commands on Cisco IOS XR Software
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Cisco Express Forwarding Commands on Cisco IOS XR Software
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DHCP Commands on Cisco IOS XR Software
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Host Services and Applications Commands on Cisco IOS XR Software
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HSRP Commands on Cisco IOS XR Software
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LPTS Commands on Cisco IOS XR Software
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Network Stack IPv4 and IPv6 Commands on Cisco IOS XR Software
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Prefix List Commands on Cisco IOS XR Software
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Transport Stack Commands on Cisco IOS XR Software
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VRRP Commands on Cisco IOS XR Software
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Index
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Table Of Contents
Network Stack IPv4 and IPv6 Commands on Cisco IOS XR Software
icmp ipv4 rate-limit unreachable
ipv4 unnumbered (point-to-point)
show arm registrations producers
Network Stack IPv4 and IPv6 Commands on Cisco IOS XR Software
This chapter describes the commands available in the Cisco IOS XR software to configure and monitor features related to IP Version 4 (IPv4) and IP Version 6 (IPv6).
For detailed information about network stack concepts, configuration tasks, and examples, refer to the Implementing Network Stack IPv4 and IPv6 on Cisco IOS XR Software configuration module.
clear ipv6 neighbors
To delete all entries in the IPv6 neighbor discovery cache, except static entries, use the clear ipv6 neighbors command in EXEC mode.
clear ipv6 neighbors [location node-id]
Syntax Description
location node-id
(Optional) The designated node. The node-id argument is entered in the rack/slot/module notation.
Defaults
No default behavior or values
Command Modes
EXEC
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
If the location option is specified, only the neighbor entries specified in the location node-id keyword and argument are cleared.
Task ID
Examples
In the following example, only the highlighted entry is deleted:
RP/0/RP0/CPU0:router# clear ipv6 neighbors ?location specify a node nameRP/0/RP0/CPU0:router# show ipv6 neighborIPv6 Address Age Link-layer Addr State Interface8888::3 - 1234.2345.9877 REACH POS 0/0/0/08888::8 - 1234.2345.9877 REACH POS0 /0/0/0fe80::205:1ff:fe9f:6400 1335 0005.019f.6400 STALE POS 0/0/0/0fe80::206:d6ff:fece:3808 1482 0006.d6ce.3808 STALE POS 0/0/0/0fe80::200:11ff:fe11:1112 1533 0000.1111.1112 STALE POS 0/2/0/2RP/0/RP0/CPU0:router# clear ipv6 neighbors location 0/2/0RP/0/RP0/CPU0:router# show ipv6 neighborIPv6 Address Age Link-layer Addr State Interface8888::3 - 1234.2345.9877 REACH POS 0/0/0/08888::8 - 1234.2345.9877 REACH POS 0/0/0/0fe80::205:1ff:fe9f:6400 1387 0005.019f.6400 STALE POS 0/0/0/0fe80::206:d6ff:fece:3808 1534 0006.d6ce.3808 STALE POS 0/0/0/0icmp ipv4 rate-limit unreachable
To limit the rate that IPv4 Internet Control Message Protocol (ICMP) destination unreachable messages are generated, use the icmp ipv4 rate-limit unreachable command in global configuration mode. To remove the rate limit, use the no form of this command.
icmp ipv4 rate-limit unreachable [DF] milliseconds
no icmp ipv4 rate-limit unreachable [DF] milliseconds
Syntax Description
Defaults
The default value is one ICMP destination unreachable message every 500 milliseconds.
Command Modes
Global configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
The Cisco IOS XR software maintains two timers: one for general destination unreachable messages and one for DF destination unreachable messages. Both share the same time limits and defaults. If the DF option is not configured, the icmp ipv4 rate-limit unreachable command sets the time values for DF destination unreachable messages. If the DF option is configured, its time values remain independent from those of general destination unreachable messages.
Task ID
Examples
The following example shows how to set the rate of the ICMP destination unreachable message to one message every 10 milliseconds:
RP/0/RP0/CPU0:router(config)# icmp ipv4 rate-limit unreachable 10ipv4 address (network)
To set a primary or secondary IPv4 address for an interface, use the ipv4 address command in interface configuration mode. To remove an IPv4 address, use the no form of this command.
ipv4 address ipv4-address mask [secondary]
no ipv4 address ipv4-address mask [secondary]
Syntax Description
Defaults
No IPv4 address is defined for the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
An interface can have one primary IPv4 address and multiple secondary IPv4 addresses. Packets generated by the software always use the primary IPv4 address. Therefore, all networking devices on a segment should share the same primary network number.
Note
The same IPv4 address configured on two different interfaces causes an error message to display that indicates the conflict. The interface located in the highest rack, slot, module, instance, and port is disabled.
Hosts can determine subnet masks using the IPv4 Internet Control Message Protocol (ICMP) mask request message. Networking devices respond to this request with an ICMP mask reply message.
You can disable IPv4 processing on a particular interface by removing its IPv4 address with the no ipv4 address command. If the software detects another host using one of its IPv4 addresses, it will display an error message on the console.
The optional secondary keyword allows you to specify an unlimited number of secondary addresses. Secondary addresses are treated like primary addresses, except that the system never generates datagrams other than routing updates with secondary source addresses. IPv4 broadcasts and Address Resolution Protocol (ARP) requests are handled properly, as are interface routes in the IP routing table.
Secondary IPv4 addresses can be used in a variety of situations. The following are the most common applications:
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Task ID
Examples
The following example shows how to set 192.168.1.27 as the primary address and 192.168.7.17 and 192.168.8.17 as the secondary addresses on POS interface 0/1/1/0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 address 192.168.1.27 255.255.255.0RP/0/RP0/CPU0:router(config-if)# ipv4 address 192.168.7.17 255.255.255.0 secondaryRP/0/RP0/CPU0:router(config-if)# ipv4 address 192.168.8.17 255.255.255.0 secondaryRelated Commands
ipv4 assembler max-packets
To configure the maximum number of packets that are allowed in assembly queues, use the ipv4 assembler max-packets command in global configuration mode. To disable this feature, use the no from of this command.
ipv4 assembler max-packets percentage value
no ipv4 assembler max-packets percentage value
Syntax Description
Command Modes
Global configuration
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to configure the maximum number of packets for the assembly queue:
RP/0/RP0/CPU0:router(config)# ipv4 assembler max-packets 35Related Commands
Configures the number of seconds an assembly queue can hold before a timeout occurs.
ipv4 assembler timeout
To configure the number of seconds an assembly queue can hold before a timeout occurs, use the ipv4 assembler timeout command in global configuration mode. To disable this feature, use the no form of this command.
ipv4 assembler timeout seconds
no ipv4 assembler timeout seconds
Syntax Description
seconds
Number of seconds an assembly queue can hold before a timeout occurs. The range is from 1 to 120.
Command Modes
Global configuration
Command History
Release 3.6.0
This command was introduced on the Cisco CRS-1 and Cisco XR 12000 Series Router.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Task ID
Examples
The following example shows how to configure an assembly queue before a timeout occurs:
RP/0/RP0/CPU0:router(config)# ipv4 assembler timeout 88Related Commands
ipv4 conflict-policy
To enable IP Address Repository Manager (IPARM) conflict resolution, use the ipv4 conflict-policy command in global configuration mode. To disable the IPARM conflict resolution, use the no form of the command.
ipv4 conflict-policy {highest-ip | longest-prefix | static}
no ipv4 conflict-policy {highest-ip | longest-prefix | static}
Syntax Description
Defaults
The precedence rule adopted is loopback > physical > other virtual interfaces. Within virtual interfaces, there is an alphabetical preference, for example, loopback1 > loopback2 and bundle-ether > bundle-pos > tunnel. Among physical interfaces, the lower rack or slot takes control.
Command Modes
Global configuration
Command History
Release 3.3.0
No modification.
Release 3.4.0
No modification.
Release 3.5.0
No modification.
Release 3.6.0
No modification.
Release 3.7.0
No modification.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Use ipv4 conflict-policy command to set an IPARM policy that resolves a conflict in the configured addresses. The policy tells IPARM what address to select from the addresses in conflict. The policy then forces the address in conflict to become inactive.
Task ID
Examples
The following example shows how to enable the static policy for conflict resolution:
RP/0/RP0/CPU0:router(config)# ipv6 conflict-policy staticRelated Commands
ipv4 directed-broadcast
To enable forwarding of IPv4 directed broadcasts on an interface, use the ipv4 directed-broadcast command in interface configuration mode. To disable forwarding of IPv4 directed broadcast on an interface, use the no form of this command.
ipv4 directed-broadcast
no ipv4 directed-broadcast
Syntax Description
This command has no arguments or keywords.
Defaults
By default, directed broadcasts are dropped.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
A directed broadcast is a packet sent to a specific network. IPv4 directed broadcasts are dropped and not forwarded. Dropping IPv4 directed broadcasts makes routers less susceptible to denial-of-service (DoS) attacks.
Task ID
Examples
The following example shows how to enable the forwarding of IPv4 directed broadcasts on POS interface 0/1/1/0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 directed-broadcastRelated Commands
Enables IP processing on a point-to-point interface without assigning an explicit IP address to the interface.
Lists a summary of IPv4 information and status for the interface.
ipv4 helper-address
To configure the address to which the software forwards User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ipv4 helper-address command in interface configuration mode. To remove an IPv4 helper address, use the no form of this command.
ipv4 helper-address [vrf vrf-name] | [destination-address]
no ipv4 helper-address [vrf vrf-name] | [destination-address]
Syntax Description
Defaults
IPv4 helper addresses are disabled. Default vrf is assumed if the vrf is not specified.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Use this command with the forward-protocol udp command in global configuration mode, which specifies by port number the broadcast packets that are forwarded. UDP is enabled by default for well-known ports. The ipv4 helper-address command specifies the destination to which the UDP packets are forwarded.
One common application that requires IPv4 helper addresses is Dynamic Host Configuration Protocol (DHCP), which is defined in RFC 1531. DHCP protocol information is carried inside of BOOTP packets. To enable BOOTP broadcast forwarding for a set of clients, configure an IPv4 helper address on the networking device interface physically closest to the client. The IPv4 helper address should specify the address of the DHCP server. If you have multiple servers, you can configure one IPv4 helper address for each server. Because BOOTP packets are forwarded by default, DHCP information can now be forwarded by the networking device. The DHCP server now receives broadcasts from the DHCP clients.
Task ID
Examples
The following example shows how to specify that all UDP broadcast packets received on POS interface 0/1/1/0 are forwarded to 192.168.1.0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 helper-address 192.168.1.0Related Commands
Specifies which ports the networking device forwards to when forwarding broadcast packets.
ipv4 mask-reply
To enable the Cisco IOS XR software to respond to IPv4 Internet Control Message Protocol (ICMP) mask requests by sending ICMP mask reply messages, use the ipv4 mask-reply command in interface configuration mode. To restore the default, use the no form of this command.
ipv4 mask-reply
no ipv4 mask-reply
Syntax Description
This command has no arguments or keywords.
Defaults
IPv4 mask replies are not sent.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
This command enables the Cisco IOS XR software to respond to IPv4 ICMP mask requests by sending ICMP mask reply messages.
Task ID
Examples
The following example enables the sending of ICMP mask reply messages on POS interface 0/1/1/0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 mask-replyipv4 mtu
To set the maximum transmission unit (MTU) size of IPv4 packets sent on an interface, use the ipv4 mtu command in interface configuration mode. To restore the default MTU size, use the no form of this command.
ipv4 mtu bytes
no ipv4 mtu
Syntax Description
bytes
MTU in bytes. Range is 68 to 65535 bytes for IPv4 packets. The maximum MTU size that can be set on an interface depends on the interface medium.
Defaults
If no MTU size is configured for IPv4 packets sent on an interface, the interface derives the MTU from the Layer 2 MTU.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
The router will fragment any IPv4 packet that exceeds the MTU set for the interface.
The maximum MTU size that can be set on an interface depends on the interface medium. If the Layer 2 MTU is smaller than the Layer 3 MTU, the Cisco IOS XR software uses the Layer 2 MTU value for the Layer 3 MTU. Conversely, if the Layer 3 MTU is smaller than the Layer 2 MTU, the software uses Layer 3 MTU value. In other words the Cisco IOS XR software uses the lower of the two values for the MTU.
All devices on a physical medium must have the same protocol MTU to operate.
Note
Task ID
Examples
The following example shows how to set the maximum IPv4 packet size for POS interface 0/1/1/0 to 300 bytes:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 mtu 300Related Commands
ipv4 redirects
To enable the sending of IPv4 Internet Control Message Protocol (ICMP) redirect messages if the software is forced to resend a packet through the same interface on which it was received, use the ipv4 redirects command in interface configuration mode. To restore the default, use the no form of this command.
ipv4 redirects
no ipv4 redirects
Syntax Description
This command has no arguments or keywords.
Defaults
ICMP redirect messages are disabled by default on the interface unless the Hot Standby Router Protocol (HSRP) is configured.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
If HSRP is configured on an interface, ICMP redirect messages are disabled by default on that interface.
Task ID
Examples
The following example shows how to disable the sending of ICMP IPv4 redirect messages on POS interface 0/1/1/0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 redirectsipv4 source-route
To allow the processing of any IPv4 datagrams containing a source-route header option, use the ipv4 source-route command in global configuration mode. To have the software discard any IP datagram that contains a source-route option, use the no form of this command.
ipv4 source-route
no ipv4 source-route
Syntax Description
This command has no arguments or keywords.
Defaults
The software discards any IPv4 datagrams containing a source-route header option.
Command Modes
Global configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
By default, any IPv4 datagram which contains a source-route header option is discarded.
Task ID
Examples
The following example shows how to allow the processing of any IPv4 datagrams containing a source-route header option:
RP/0/RP0/CPU0:router(config)# ipv4 source-routeipv4 unnumbered (point-to-point)
To enable IPv4 processing on a point-to-point interface without assigning an explicit IPv4 address to that interface, use the ipv4 unnumbered command in interface configuration mode. To disable this feature, use the no form of this command.
ipv4 unnumbered interface-type interface-instance
no ipv4 unnumbered interface-type interface-instance
Syntax Description
Defaults
IPv4 processing on a point-to-point interface is disabled unless an IPv4 address is assigned explicitly to that interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
Whenever the unnumbered interface generates a packet (for example, for a routing update), it uses the address of the specified interface as the source address of the IPv4 packet. It also uses the IPv4 address of the specified interface in determining which routing processes are sending updates over the unnumbered interface. Restrictions include the following:
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The interface you specify by the interface-type and interface-number arguments must be enabled (listed as "up" in the show interfaces command display).
If you are configuring Intermediate System-to-Intermediate System (IS-IS) across a POS interface, you should configure the POS interface as unnumbered. This strategy allows you to conform to RFC 1195, which states that IP addresses are not required on each interface.
Task ID
Examples
In the following example, POS interface 0/1/1/0 is assigned the loopback interface address 5:
RP/0/RP0/CPU0:router(config)# interface loopback 5RP/0/RP0/CPU0:router(config-if)# ipv4 address 192.168.6.6 255.255.255.0RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 unnumbered loopback 5ipv4 unreachables disable
To disable the generation of IPv4 Internet Control Message Protocol (ICMP) unreachable messages, use the ipv4 unreachables command in interface configuration mode. To re-enable the generation of ICMP unreachable messages, use the no form of this command.
ipv4 unreachables disable
no ipv4 unreachables disable
Syntax Description
This command has no arguments or keywords.
Defaults
IPv4 ICMP unreachables messages are generated.
Command Modes
Interface configuration
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.
If the software receives a nonbroadcast packet destined for itself that uses a protocol it does not recognize, it sends an ICMP protocol unreachable message to the source.
If the software receives a datagram that it cannot deliver to its ultimate destination because it knows of no route to the destination address, it replies to the originator of that datagram with an ICMP host unreachable message.
This command affects a number of ICMP unreachable messages.
Task ID
Examples
The following example shows how to disable the generation of ICMP unreachable messages on POS interface 0/1/1/0:
RP/0/RP0/CPU0:router(config)# interface POS 0/1/1/0RP/0/RP0/CPU0:router(config-if)# ipv4 unreachables disableipv4 virtual address
To define an IPv4 virtual address for a network of management Ethernet interfaces, use the ipv4 virtual interface command in global configuration mode. To remove an IPv4 virtual address from the configuration, use the no form of this command.
ipv4 virtual address [vrf vrf-name] {ipv4-address/mask}
no ipv4 virtual address [vrf vrf-name] {ipv4-address/mask}
Syntax Description
Defaults
No IPv4 virtual address is defined for the configuration.
Command Modes
Global configuration
Command History
