Interface information not updated in single hop BFD sessions for v6 sessions in frr 8.2.2

[rera1712]

FRR VERSION
frr 8.2.2

• OPERATING SYSTEM VERSION
  Linux 55d7473a7f81 5.11.22-100.fc32.x86_64 A small collection of patches that fix issues found by valgrind #1 SMP Wed May 19 18:58:25 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

To Reproduce

Router 1-----------------Router 2
1.Enable BFD on bgp neighbor
2.Add ip addresses on the local interfaces configured
3.Configure/update the bfd sessions created from step 1 with some new timer values
4.Verify bfd sessions using "show bfd peers"

Expected:
"show bfd peers" should show interface and peer address.
Actual:
"show bfd peers" shows only peer address and interface information is missing.

Did you check if this is a duplicate issue?
I did not see any issues similar to this reported
Did you test it on the latest FRRouting/frr master branch?
No

config Router 1:
8630fcc8739c# show running-config
Building configuration...

Current configuration:
!
frr version 8.2.2
frr defaults traditional
hostname 8630fcc8739c
log file /var/log/frr/frr.log
log timestamp precision 3
!
password frrpass
enable password frrpass
!
interface sw1p0
ip address 10.0.12.0 peer 10.0.12.1/31
ipv6 address 2000::1/64
mpls bgp forwarding
exit
!
router bgp 65590
bgp router-id 0.0.0.1
no bgp ebgp-requires-policy
no bgp suppress-duplicates
no bgp default ipv4-unicast
no bgp network import-check
neighbor 10.0.12.1 remote-as 65591
neighbor 10.0.12.1 bfd
neighbor 10.0.12.1 solo
neighbor 10.0.12.1 disable-connected-check
neighbor 10.0.12.1 update-source 10.0.12.0
neighbor 2000::2 remote-as 65591
neighbor 2000::2 bfd
neighbor 2000::2 solo
neighbor 2000::2 disable-connected-check
neighbor 2000::2 update-source 2000::1
!
address-family ipv4 unicast
neighbor 10.0.12.1 activate
neighbor 10.0.12.1 filter-list ebgp-export-neigh-10.0.12.1-v4 out
neighbor 2000::2 activate
neighbor 2000::2 filter-list ebgp-export-neigh-2000::2-v4 out
exit-address-family
!
address-family ipv6 unicast
neighbor 10.0.12.1 activate
neighbor 10.0.12.1 filter-list ebgp-export-neigh-10.0.12.1-v6 out
neighbor 2000::2 activate
neighbor 2000::2 filter-list ebgp-export-neigh-2000::2-v6 out
exit-address-family
exit
!
bgp as-path access-list ebgp-export-neigh-10.0.12.1-v4 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-10.0.12.1-v6 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-2000::2-v4 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-2000::2-v6 seq 5 permit ^$
!
bfd
peer 10.0.12.1 interface sw1p0
transmit-interval 150
receive-interval 150
exit
!
peer 2000::2 interface sw1p0
detect-multiplier 2
transmit-interval 150
receive-interval 150
exit
!
exit
!
end
8630fcc8739c#

config: Router 2
11798bc5ec06# show running-config
Building configuration...

Current configuration:
!
frr version 8.2.2
frr defaults traditional
hostname 11798bc5ec06
log file /var/log/frr/frr.log
log timestamp precision 3
!
password frrpass
enable password frrpass
!
interface sw1p0
ip address 10.0.12.1 peer 10.0.12.0/31
ipv6 address 2000::2/64
mpls bgp forwarding
exit
!
router bgp 65591
bgp router-id 0.0.0.3
no bgp ebgp-requires-policy
no bgp suppress-duplicates
no bgp default ipv4-unicast
no bgp network import-check
neighbor 10.0.12.0 remote-as 65590
neighbor 10.0.12.0 bfd
neighbor 10.0.12.0 solo
neighbor 10.0.12.0 disable-connected-check
neighbor 10.0.12.0 update-source 10.0.12.1
neighbor 2000::1 remote-as 65590
neighbor 2000::1 bfd
neighbor 2000::1 solo
neighbor 2000::1 disable-connected-check
neighbor 2000::1 update-source 2000::2
!
address-family ipv4 unicast
neighbor 10.0.12.0 activate
neighbor 10.0.12.0 filter-list ebgp-export-neigh-10.0.12.0-v4 out
neighbor 2000::1 activate
neighbor 2000::1 filter-list ebgp-export-neigh-2000::1-v4 out
exit-address-family
!
address-family ipv6 unicast
neighbor 10.0.12.0 activate
neighbor 10.0.12.0 filter-list ebgp-export-neigh-10.0.12.0-v6 out
neighbor 2000::1 activate
neighbor 2000::1 filter-list ebgp-export-neigh-2000::1-v6 out
exit-address-family
exit
!
bgp as-path access-list ebgp-export-neigh-10.0.12.0-v4 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-10.0.12.0-v6 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-2000::1-v4 seq 5 permit ^$
bgp as-path access-list ebgp-export-neigh-2000::1-v6 seq 5 permit ^$
!
bfd
peer 10.0.12.0 interface sw1p0
transmit-interval 150
receive-interval 150
exit
!
peer 2000::1 interface sw1p0
detect-multiplier 2
transmit-interval 150
receive-interval 150
exit
!
exit
!
end
11798bc5ec06#

BFD peers in Router 2:

11798bc5ec06# show bfd peers
BFD Peers:
peer 2000::1 vrf default
ID: 3372052738
Remote ID: 2174145595
Active mode
Status: up
Uptime: 17 minute(s), 57 second(s)
Diagnostics: ok
Remote diagnostics: ok
Peer Type: configured
Local timers:
Detect-multiplier: 2
Receive interval: 150ms
Transmission interval: 150ms
Echo receive interval: 50ms
Echo transmission interval: disabled
Remote timers:
Detect-multiplier: 2
Receive interval: 150ms
Transmission interval: 150ms
Echo receive interval: 50ms

peer 10.0.12.0 local-address 10.0.12.1 vrf default interface sw1p0
	ID: 1953417150
	Remote ID: 1642542543
	Active mode
	Status: up
	Uptime: 17 minute(s), 57 second(s)
	Diagnostics: ok
	Remote diagnostics: ok
	Peer Type: configured
	Local timers:
		Detect-multiplier: 3
		Receive interval: 150ms
		Transmission interval: 150ms
		Echo receive interval: 50ms
		Echo transmission interval: disabled
	Remote timers:
		Detect-multiplier: 3
		Receive interval: 150ms
		Transmission interval: 150ms
		Echo receive interval: 50ms

BFD Peers in Router 1:

8630fcc8739c# show bfd peers
BFD Peers:
peer 10.0.12.1 local-address 10.0.12.0 vrf default interface sw1p0
ID: 1642542543
Remote ID: 1953417150
Active mode
Status: up
Uptime: 18 minute(s), 37 second(s)
Diagnostics: ok
Remote diagnostics: ok
Peer Type: configured
Local timers:
Detect-multiplier: 3
Receive interval: 150ms
Transmission interval: 150ms
Echo receive interval: 50ms
Echo transmission interval: disabled
Remote timers:
Detect-multiplier: 3
Receive interval: 150ms
Transmission interval: 150ms
Echo receive interval: 50ms

peer 2000::2 vrf default
	ID: 2174145595
	Remote ID: 3372052738
	Active mode
	Status: up
	Uptime: 18 minute(s), 37 second(s)
	Diagnostics: ok
	Remote diagnostics: ok
	Peer Type: configured
	Local timers:
		Detect-multiplier: 2
		Receive interval: 150ms
		Transmission interval: 150ms
		Echo receive interval: 50ms
		Echo transmission interval: disabled
	Remote timers:
		Detect-multiplier: 2
		Receive interval: 150ms
		Transmission interval: 150ms
		Echo receive interval: 50ms

The problem I see after ip address configured on local interface, there is a delay of 700ms for zebra to send notification to bfd for deleting the old session without interface and add the new session with interface, Meanwhile if an update comes for the same bfd session then the refcount is increased for the old sessions and existing session without interface is updated instead of creating a new session with interface.
For ipv4 the notification from zebra to bfd comes immediately but for ipv6 the notification of local address configuration comes little later which is causing this.

FRR logs:

2022/09/21 01:47:34.878 BFD: [G1AWQ-Y8T4P] ptm ref count increased for discriminator-2039740559 1
2022/09/21 01:47:34.962 BFD: [G1AWQ-Y8T4P] ptm ref count increased for discriminator105903443 1
2022/09/21 01:48:13.815 BFD: [Q42XY-M09HE] packet-send: send failure: Network is unreachable
2022/09/21 01:48:37.455 ZEBRA: [NBGDS-5ZDQ9] MESSAGE: ZEBRA_INTERFACE_ADDRESS_ADD 10.0.12.0/32 on sw1p0 vrf default(0)
2022/09/21 01:48:37.455 BFD: [SSYGJ-9ZAE0] zclient: add local address 10.0.12.0/32 (VRF 0)
2022/09/21 01:48:37.466 BGP: [HTQD2-0R1WR][EC 33554451] bgp_process_packet: BGP OPEN receipt failed for peer: 10.0.12.1
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 1
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 2
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 3
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 4
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 5
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 6
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 7
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 1
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 2
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 3
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 4
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 5
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 6
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 7
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 1
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 2
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 3
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 4
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 5
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 6
2022/09/21 01:48:37.468 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 7
2022/09/21 01:48:37.468 BGP: [VQY9X-CQZKG] bgp_peer_bfd_update_source: address [0.0.0.0->10.0.12.1] to [10.0.12.0->10.0.12.1]
2022/09/21 01:48:37.468 BGP: [X8BD9-8RKN4] bgp_peer_bfd_update_source: interface none to sw1p0
2022/09/21 01:48:37.468 ZEBRA: [T4P6D-CDT49] bfd_dst_deregister msg from client bgp: length=30
2022/09/21 01:48:37.468 ZEBRA: [G37DH-KRAE9] bfd_dst_register msg from client bgp: length=35
2022/09/21 01:48:37.468 BFD: [MSVDW-Y8Z5Q] ptm-del-dest: deregister peer [mhop:no peer:10.0.12.1 local:0.0.0.0 vrf:default cbit:0x00 minimum-ttl:255]
2022/09/21 01:48:37.468 BFD: [QQ4FF-P6HPH] ptm ref count decreased for discriminator -2039740559 0
2022/09/21 01:48:37.468 BFD: [NYF5K-SE3NS] ptm-del-session: [mhop:no peer:10.0.12.1 local:0.0.0.0 vrf:default] refcount=0
2022/09/21 01:48:37.468 BFD: [NW21R-MRYNT] session-delete: mhop:no peer:10.0.12.1 local:0.0.0.0 vrf:default
2022/09/21 01:48:37.468 BFD: [MSVDW-Y8Z5Q] ptm-add-dest: register peer [mhop:no peer:10.0.12.1 local:10.0.12.0 vrf:default cbit:0x00 minimum-ttl:255]
2022/09/21 01:48:37.468 BFD: [PSB4R-8T1TJ] session-new: mhop:no peer:10.0.12.1 local:10.0.12.0 vrf:default ifname:sw1p0
2022/09/21 01:48:37.468 BFD: [G1AWQ-Y8T4P] ptm ref count increased for discriminator-1142479462 1
2022/09/21 01:48:37.468 ZEBRA: [V0KXZ-QFE4D] bfd_dst_update msg from client bfd: length=25
2022/09/21 01:48:37.468 BGP: [Q4BCV-6FHZ5] zclient_bfd_session_update: 10.0.12.0/32 -> 10.0.12.1/32 (interface sw1p0) VRF default(0) (CPI bit no): Down
2022/09/21 01:48:37.468 BGP: [QFMSE-NPSNN] zclient_bfd_session_update: sessions updated: 0
2022/09/21 01:48:37.541 BFD: [SX3SB-Z96JV] nb ref count increased for discriminator-1142479462 2
2022/09/21 01:48:37.582 BFD: [SX3SB-Z96JV] nb ref count increased for discriminator105903443 2
2022/09/21 01:48:38.618 BGP: [M59KS-A3ZXZ] bgp_update_receive: rcvd End-of-RIB for IPv4 Unicast from 10.0.12.1 in vrf default
2022/09/21 01:48:38.618 BGP: [M59KS-A3ZXZ] bgp_update_receive: rcvd End-of-RIB for IPv6 Unicast from 10.0.12.1 in vrf default
2022/09/21 01:48:38.618 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 1
2022/09/21 01:48:38.618 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 1
2022/09/21 01:48:38.626 BFD: [J1C6V-VMRW5] state-change: [mhop:no peer:10.0.12.1 local:10.0.12.0 vrf:default ifname:sw1p0] down -> up
2022/09/21 01:48:38.626 ZEBRA: [V0KXZ-QFE4D] bfd_dst_update msg from client bfd: length=25
2022/09/21 01:48:38.626 BGP: [Q4BCV-6FHZ5] zclient_bfd_session_update: 10.0.12.0/32 -> 10.0.12.1/32 (interface sw1p0) VRF default(0) (CPI bit no): Up
2022/09/21 01:48:38.626 BGP: [MKVHZ-7MS3V] bfd_session_status_update: neighbor 10.0.12.1 vrf default(0) bfd state Down -> Up
2022/09/21 01:48:38.626 BGP: [QFMSE-NPSNN] zclient_bfd_session_update: sessions updated: 1
2022/09/21 01:48:38.908 ZEBRA: [NBGDS-5ZDQ9] MESSAGE: ZEBRA_INTERFACE_ADDRESS_ADD 2000::1/64 on sw1p0 vrf default(0)
2022/09/21 01:48:38.909 BFD: [SSYGJ-9ZAE0] zclient: add local address 2000::1/64 (VRF 0)
2022/09/21 01:48:39.484 BFD: [YA0Q5-C0BPV] control-packet: no session found [mhop:no peer:fe80::a4e9:f7ff:fe36:82b5 local:2000::1 port:2]
2022/09/21 01:48:39.484 BFD: [YA0Q5-C0BPV] control-packet: no session found [mhop:no peer:fe80::a4e9:f7ff:fe36:82b5 local:2000::1 port:2]
2022/09/21 01:48:39.485 BGP: [HTQD2-0R1WR][EC 33554451] bgp_process_packet: BGP OPEN receipt failed for peer: 2000::2
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 1
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 2
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 3
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 4
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 5
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 6
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 7
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 1
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 2
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 3
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 4
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 5
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 6
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 7
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 1
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 2
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 3
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 4
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 5
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 6
2022/09/21 01:48:39.486 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 3, SAFI 7
2022/09/21 01:48:39.487 BGP: [WJWH8-SHS78] bgp_peer_bfd_update_source: address [::->2000::2] to [2000::1->2000::2]
2022/09/21 01:48:39.487 BGP: [X8BD9-8RKN4] bgp_peer_bfd_update_source: interface none to sw1p0
2022/09/21 01:48:39.487 ZEBRA: [T4P6D-CDT49] bfd_dst_deregister msg from client bgp: length=54
2022/09/21 01:48:39.487 ZEBRA: [G37DH-KRAE9] bfd_dst_register msg from client bgp: length=59
2022/09/21 01:48:39.487 BFD: [MSVDW-Y8Z5Q] ptm-del-dest: deregister peer [mhop:no peer:2000::2 local::: vrf:default cbit:0x00 minimum-ttl:255]
2022/09/21 01:48:39.487 BFD: [QQ4FF-P6HPH] ptm ref count decreased for discriminator 105903443 1
2022/09/21 01:48:39.487 BFD: [NYF5K-SE3NS] ptm-del-session: [mhop:no peer:2000::2 local::: vrf:default] refcount=1
2022/09/21 01:48:39.487 BFD: [NW21R-MRYNT] session-delete: mhop:no peer:2000::2 local::: vrf:default
2022/09/21 01:48:39.487 BFD: [MSVDW-Y8Z5Q] ptm-add-dest: register peer [mhop:no peer:2000::2 local:2000::1 vrf:default cbit:0x00 minimum-ttl:255]
2022/09/21 01:48:39.487 BFD: [G1AWQ-Y8T4P] ptm ref count increased for discriminator105903443 2
2022/09/21 01:48:39.487 ZEBRA: [V0KXZ-QFE4D] bfd_dst_update msg from client bfd: length=49
2022/09/21 01:48:39.487 BGP: [Q4BCV-6FHZ5] zclient_bfd_session_update: ::/128 -> 2000::2/128 (interface sw1p0) VRF default(0) (CPI bit no): Down
2022/09/21 01:48:39.487 BGP: [QFMSE-NPSNN] zclient_bfd_session_update: sessions updated: 0
2022/09/21 01:48:39.529 BFD: [J1C6V-VMRW5] state-change: [mhop:no peer:2000::2 local::: vrf:default] down -> up
2022/09/21 01:48:39.529 ZEBRA: [V0KXZ-QFE4D] bfd_dst_update msg from client bfd: length=49
2022/09/21 01:48:39.529 BGP: [Q4BCV-6FHZ5] zclient_bfd_session_update: ::/128 -> 2000::2/128 (interface sw1p0) VRF default(0) (CPI bit no): Up
2022/09/21 01:48:39.529 BGP: [MKVHZ-7MS3V] bfd_session_status_update: neighbor 2000::2 vrf default(0) bfd state Down -> Up
2022/09/21 01:48:39.529 BGP: [QFMSE-NPSNN] zclient_bfd_session_update: sessions updated: 1
2022/09/21 01:48:40.636 BGP: [M59KS-A3ZXZ] bgp_update_receive: rcvd End-of-RIB for IPv4 Unicast from 2000::2 in vrf default
2022/09/21 01:48:40.636 BGP: [M59KS-A3ZXZ] bgp_update_receive: rcvd End-of-RIB for IPv6 Unicast from 2000::2 in vrf default
2022/09/21 01:48:40.637 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 1, SAFI 1
2022/09/21 01:48:40.637 ZEBRA: [ZG1NW-NBE3Z] zebra_client_update_info: Client bgp route update complete for AFI 2, SAFI 1

[rera1712]

@donaldsharp @ton31337 Do you have any suggestions on this ?

[ton31337]

Didn't have a chance to look at this yet.

[rera1712]

Sure Thanks.

I found two issues here,

1.FRR takes some ~700 to 800 milliseconds to update the bfd sessions with local ip when a ipv6 address is configured on interface.Delay is not seen during ipv4 address configuration.

2.When the north bound configuration(cli) configures an already configured session by BGP, it does a hash lookup,
with key as interface name but it fetches the session though it was not added with ifname as key.
Not sure how it works.

bfd_session_create()

   case NB_EV_PREPARE:
            bfd_session_get_key(mhop, args->dnode, &bk);
            bs = bfd_key_lookup(bk); 

            /* This session was already configured by another daemon. */
            if (bs != NULL) {
                    /* Now it is configured also by CLI. */
                    SET_FLAG(bs->flags, BFD_SESS_FLAG_CONFIG);
                    bs->refcount++;

                    args->resource->ptr = bs;
                    break;
            }

In the above code,bk.ifname has an interface but still it fetches a bfd session which is not updated with interface information

I tried a patch locally where if the existing session does not have interface and if the north bound has interface information,
I update the interface information in the bfd session keys.It works.

Please let me know your views when you check this, Thanks

[github-actions]

This issue is stale because it has been open 180 days with no activity. Comment or remove the autoclose label in order to avoid having this issue closed.