- IPv6 Routing: EIGRP Support
- EIGRP MIB
- EIGRP MPLS VPN PE-CE Site of Origin
- EIGRP Support for Route Map Filtering
- EIGRP/SAF HMAC-SHA-256 Authentication
- EIGRP Wide Metrics
- EIGRP
- EIGRP IPv6 VRF-Lite
- EIGRP Stub Routing
- IP EIGRP Route Authentication
- Configuring EIGRP
- Add Path Support in EIGRP
- BFD Support for EIGRP IPv6
- EIGRP Classic to Named Mode Conversion
- EIGRP IPv6 NSF/GR
- EIGRP Loop-Free Alternate Fast Reroute
- EIGRP Support for 6PE/6VPE
- EIGRP Route Tag Enhancements
- Finding Feature Information
- Prerequisites for EIGRP IPv6 NSF/GR
- Restrictions for EIGRP IPv6 NSF/GR
- Information About EIGRP IPv6 NSF/GR
- How to Configure EIGRP IPv6 NSF/GR
- Configuration Examples for EIGRP IPv6 NSF/GR
- Additional References for EIGRP IPv6 NSF/GR
- Feature Information for EIGRP IPv6 NSF/GR
EIGRP IPv6 NSF/GR
The EIGRP IPv6 NSF/GR feature allows a Nonstop Forwarding (NSF)-aware device that is running Enhanced Interior Gateway Routing Protocol (EIGRP) to forward IPv6 packets while EIGRP restarts after recovering from a failure.
- Finding Feature Information
- Prerequisites for EIGRP IPv6 NSF/GR
- Restrictions for EIGRP IPv6 NSF/GR
- Information About EIGRP IPv6 NSF/GR
- How to Configure EIGRP IPv6 NSF/GR
- Configuration Examples for EIGRP IPv6 NSF/GR
- Additional References for EIGRP IPv6 NSF/GR
- Feature Information for EIGRP IPv6 NSF/GR
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for EIGRP IPv6 NSF/GR
EIGRP (Enhanced Interior Gateway Routing Protocol) IPv6 must be configured on devices. You need not specify the network network-number command in EIGRP named mode. By default, EIGRP IPv6 enables EIGRP on all interfaces configured with an IPv6 address.
Cisco software that supports Nonstop Forwarding (NSF) awareness or NSF capabilities must be installed.
A redundant facility must be configured to notify EIGRP during a switchover and to notify whether the restart is due to a switchover or a device reboot.
An NSF-aware device must be up and completely converged with the network before it can assist an NSF-capable device in an NSF restart operation.
All neighboring devices participating in EIGRP NSF must be NSF-capable or NSF-aware.
Restrictions for EIGRP IPv6 NSF/GR
Nonstop Forwarding (NSF) is supported on platforms that support high-availability systems.
An Enhanced Interior Gateway Routing Protocol (EIGRP) NSF-aware network does not allow two neighbors to perform an NSF restart operation at the same time. However, neighbors can re-establish peering sessions after the NSF restart operation is complete.
NSF for IPv6 is supported only in EIGRP named mode configurations.
Information About EIGRP IPv6 NSF/GR
EIGRP IPv6 NSF/GR
The EIGRP IPv6 NSF/GR feature allows a Nonstop Forwarding (NSF)-aware device that is running Enhanced Interior Gateway Routing Protocol (EIGRP) to forward IPv6 packets along routes that are known to a device that is performing a switchover operation. EIGRP peers retain adjacencies and routes learned from a restarting peer (the device that is undergoing a switchover), and the EIGRP peers continue to forward IPv6 packets to the restarting peer. The high-availability systems on the device retain the forwarding table and continue to forward IPv6 packets until the control plane (EIGRP) has converged on the restarting device.
NSF allows forwarding of IPv6 packets while the device restarts after a failure. Graceful Restart (GR) allows topology databases to resynchronize while maintaining neighbor relationships and forwarding paths.
Note | NSF supports IPv4 in EIGRP classic mode and named mode configurations. NSF supports IPv6 in named mode. For more information about the EIGRP IPv4 NSF feature, see the “EIGRP Nonstop Forwarding Awareness” module in the IP Routing: EIGRP Configuration Guide. |
EIGRP IPv6 NSF Timers
The EIGRP IPv6 NSF/GR feature supports three types of timers: the signal timer, the converge timer, and the graceful-restart purge-time timer.
Configure the signal timer to adjust the maximum time of the initial restart period. The restarting device sends hello packets with the restart-signal (RS) bit set. If the restarting device has not learned about any neighbor or any Nonstop Forwarding (NSF)-aware neighbor or has not received all updates from neighbors when the timer expires, the Routing Information Base (RIB) is notified for convergence. The default value for the signal timer is 20 seconds. The timers nsf signal command is used to configure the signal timer.
Configure the converge timer to adjust the maximum time that a restarting device waits for the end-of-table (EOT) indications from all neighbors. The default value for the converge timer is 120 seconds. The timers nsf converge command is used to configure the converge timer.
Configure the graceful-restart purge-time timer to adjust the maximum waiting time to receive the convergent signal from a restarting device. The graceful-restart purge-time timer is used when the NSF-aware peer does not receive the EOT indication from the restarting neighbor. When the graceful-restart purge-time timer expires, the Enhanced Interior Gateway Routing Protocol (EIGRP) peer scans the topology table for stale routes from the restarting neighbor and changes the stale routes to active. This process allows EIGRP peers to find alternate routes instead of waiting during a long switchover operation. The default value for the graceful-restart purge-time timer is 240 seconds. The timers graceful-restart purge-time command is used to configure the graceful-restart purge-time timer.
How to Configure EIGRP IPv6 NSF/GR
Enabling EIGRP IPv6 NSF/GR
1.
enable
2.
configure
terminal
3.
router
eigrp
name
4.
address-family
ipv6
autonomous-system
number
5.
nsf
6.
end
DETAILED STEPS
Modifying EIGRP IPv6 NSF Timers
Perform this task to modify EIGRP IPv6 NSF timers. This task is optional.
1.
enable
2.
configure
terminal
3.
router
eigrp
name
4.
address-family
ipv6
autonomous-system
number
5.
timers
nsf
signal
seconds
6.
timers
nsf
converge
seconds
7.
timers
graceful-restart
purge-time
seconds
8.
end
DETAILED STEPS
Verifying the EIGRP IPv6 NSF/GR Configuration
1.
enable
2.
show
ipv6
protocols
DETAILED STEPS
Command or Action | Purpose |
---|
Monitoring EIGRP IPv6 NSF/GR Events
1.
enable
2.
debug
eigrp
nsf
3.
debug
eigrp
address-family
ipv6
notifications
DETAILED STEPS
Configuration Examples for EIGRP IPv6 NSF/GR
Example: Configuring an EIGRP NSF Converge Timer
The following example shows how to adjust the maximum time that the restarting router waits for end-of-table (EOT) indications from all neighbors:
Device> enable Device# configure terminal Device(config)# router eigrp name Device(config-router)# address-family ipv6 autonomous system 1 Device(config-router-af)# timers nsf converge 60 Device(config-router-af)# end
Example: Verifying the Configuration of EIGRP IPv6 NSF/GR on an NSF-Aware Device
The following is a sample output from the show ipv6 protocols command, which shows that EIGRP NSF is enabled, the graceful-restart purge-time timer is set to 260 seconds, the signal timer is set to 15 seconds, and the converge timer is set to 65 seconds:
Device> enable Device# show ipv6 protocols IPv6 Routing Protocol is "connected" IPv6 Routing Protocol is "bgp 1" IGP synchronization is disabled Redistribution: None IPv6 Routing Protocol is "bgp multicast" IPv6 Routing Protocol is "ND" IPv6 Routing Protocol is "eigrp 1" EIGRP-IPv6 VR(name) Address-Family Protocol for AS(1) Metric weight K1=1, K2=0, K3=1, K4=0, K5=0 K6=0 Metric rib-scale 128 Metric version 64bit NSF-aware route hold timer is 260 EIGRP NSF enabled NSF signal timer is 15s NSF converge timer is 65s Router-ID: 10.1.1.1 Topology : 0 (base) Active Timer: 3 min Distance: internal 90 external 170 Maximum path: 16 Maximum hopcount 100 Maximum metric variance 1 Total Prefix Count: 0 Total Redist Count: 0 Interfaces: Redistribution: None
Additional References for EIGRP IPv6 NSF/GR
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Cisco Express Forwarding (formerly known as CEF) commands |
|
EIGRP commands |
|
Nonstop Forwarding (NSF) |
|
Command Lookup Tool |
Standards and RFCs
Standard/RFC |
Title |
---|---|
RFC 4724 |
Graceful Restart Mechanism for BGP |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for EIGRP IPv6 NSF/GR
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
EIGRP IPv6 NSF/GR |
15.2(1)SY |
The EIGRP IPv6 NSF/GR feature allows an NSF-aware router that is running EIGRP to forward IPv6 packets while the control plane restarts after recovering from a failure. The following commands were introduced or modified: debug eigrp nsf, nsf, show ipv6 protocols, timers graceful-restart purge-time, timers nsf converge, timers nsf signal. |