Configuring Ipv6 Is-Is Frr; Configuration Prerequisites - HP FlexFabric 12900E Series Configuration Manual

Step
2. Enable an IS-IS process and
enter IS-IS view.
3. Configure the NET for the
IS-IS process.
4. Enter IPv6 address family
view.
5. Return to system view.
6. Enter interface view.
7. Enable IPv6 for IS-IS on the
interface.
8. Enable BFD for IPv6 IS-IS.

Configuring IPv6 IS-IS FRR

IMPORTANT:
ECMP routes do not support FRR.
A link or router failure on a path can cause packet loss and routing loop. IPv6 IS-IS FRR enables fast
rerouting to minimize the failover time.
Figure 105 Network diagram for IPv6 IS-IS FRR
In Figure 105, after you enable FRR on Router B, IPv6 IS-IS FRR automatically calculates or
designates a backup next hop when a link failure is detected. In this way, packets are directed to the
backup next hop to reduce traffic recovery time. Meanwhile, IPv6 IS-IS calculates the shortest path
based on the new network topology, and forwards packets over the path after network convergence.
You can assign a backup next hop for IPv6 IS-IS FRR in the following ways:
•
Enable IPv6 IS-IS FRR to calculate a backup next hop through Loop Free Alternate (LFA)
calculation.
•
Designate a backup next hop with a routing policy for routes matching specific criteria.

Configuration prerequisites

Before you configure IPv6 IS-IS FRR, complete the following tasks:
•
Configure IPv6 addresses for interfaces to ensure IP connectivity between neighboring nodes.
•
Enable IPv6 IS-IS.
•
Make sure the backup next hop is reachable.
Command
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
network-entity net
address-family ipv6 [ unicast ]
quit
interface
interface-number
isis ipv6 enable [ process-id ]
isis ipv6 bfd enable
Backup next hop: Router C
Router B
interface-type
Next hop: Router D Router E
452
Remarks
N/A
By default, no NET is configured.
N/A
N/A
N/A
By default, IPv6 is disabled for
IS-IS on an interface.
By default, BFD for IPv6 IS-IS is
disabled.