IPv6 Loopback /64 route is not getting advertised to the neighbors

[SuvarnaMeenakshi]

Description

Steps to reproduce the issue:

1. bring up a VS testbed with latest master branch image
   ./testbed-cli.sh -t vtestbed.yaml -m veos_vtb -k ceos add-topo vms-kvm-t0 password.txt

IPv6 loopback of SONiC VS is not reachable from ceos neighbors.

Describe the results you received:

IPv6 Loopback is not advertised to ceos neighbors.
Loopback0 configuration in config_db:
"Loopback0|FC0A:1::32/128": {}

vtysh output:

vlab-01# show bgp ipv6 fc0a:1::/64
BGP routing table entry for fc0a:1::/64, version 0
Paths: (1 available, no best path)
  Not advertised to any peer
  Local
    :: (inaccessible) from :: (10.1.0.32)
      Origin IGP, metric 0, weight 32768, invalid, sourced, local
      Last update: Mon Jul  3 23:00:48 2023

Error log in zebra.log

0:254:fc0a:1::/64: Failed to enqueue dataplane install

Static route configured for loopback /64 route is not installed correctly in frr, but is installed in kernel.

vtysh -c "show ipv6 route nexthop-group"

..q - queued..

 

C>* fc00::7c/126 (526) is directly connected, PortChannel104, 00:46:17
C>* fc02:1000::/64 (453) is directly connected, Vlan1000, 00:46:20
S>q fc0a:1::/64 [1/0] (648) is directly connected, Loopback0, weight 1, 00:05:19
C>* fc0a:1::32/128 (465) is directly connected, Loopback0, 00:46:20

ip -6 route show fc0a:1::/64
fc0a:1::/64 nhid 43 dev Loopback0 proto 196 metric 20 pref medium

Describe the results you expected:

Output of show version:

(paste your output here)

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[SuvarnaMeenakshi]

@arlakshm @prsunny @StormLiangMS please check

[tjchadaga]

@SuvarnaMeenakshi - should be fixed by #15688. Please verify

[SuvarnaMeenakshi]

Verified image with fix #15688
Issue is not seen.

vtysh -c "show ipv6 route nexthop-group" 
..
C>* fc00::7c/126 (349) is directly connected, PortChannel104, 00:30:00
**S>* fc00:1::/64 [1/0]** (224) is directly connected, Loopback0, weight 1, 00:30:05
C>* fc00:1::32/128 (223) is directly connected, Loopback0, 00:30:05
C>* fc02:1000::/64 (232) is directly connected, Vlan1000, 00:30:00

admin@vlab-01:~$ vtysh -c "show bgp ipv6 fc00:1::/64"
BGP routing table entry for fc00:1::/64, version 1
Paths: (1 available, best #1, table default)
  Advertised to non peer-group peers:
  fc00::72 fc00::76 fc00::7a fc00::7e
  Local
    :: from :: (10.1.0.32)
      Origin IGP, metric 0, weight 32768, valid, sourced, local, best (First path received)
      Last update: Wed Jul  5 20:57:42 2023

ping from neighbor ceos works -

ARISTA01T1#ping fc00:1::32
PING fc00:1::32(fc00:1::32) 72 data bytes
80 bytes from fc00:1::32: icmp_seq=1 ttl=64 time=1.33 ms
80 bytes from fc00:1::32: icmp_seq=2 ttl=64 time=0.913 ms
80 bytes from fc00:1::32: icmp_seq=3 ttl=64 time=0.574 ms
80 bytes from fc00:1::32: icmp_seq=4 ttl=64 time=0.556 ms
80 bytes from fc00:1::32: icmp_seq=5 ttl=64 time=0.643 ms

--- fc00:1::32 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4ms