[BFD] Error specified interface doesn't exists

[Krisscut]

Description

Hello,

Since I made a recent upgrade from FRR 8.0.1 to 10.2.1, I have a sporadic (but quite frequent) issue when trying to setup a BFD configuration. I still reproduce it on latest version.

The configuration is done through vtysh to rewrite it at runtime.

Sporadically, my test will fail and I noticed that the main difference in FRR's logs is the presence of this error message in failure case:

session-enable: specified interface eth1.295 (VRF default) doesn't exist

When this occurs, my bfd peers stays down, and I assume this is because configuration is dropped.

If right before configuring FRR/BFD, I run through vtysh "show interface", all the interfaces seems available, so not sure why it fails to find it in FRR's internal data structure. (See attached files for FRR configuration, FRR logs, ip state & interface view)

Version

FRRouting 10.2.1 (6608e5b42472) on Linux(6.9.12-1.NSN.el8.x86_64).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
configured with:
'PERL=/usr/bin/perl' 'PYTHON=cross-python3.12' '--prefix=/opt/UE_APP_OAM' '--libdir=/opt/UE_APP_OAM/lib64' '--bindir=/opt/UE_APP_OAM/bin' '--sysconfdir=/etc/frr' '--localstatedir=/var/run/frr' '--sbindir=/opt/UE_APP_OAM/bin' '--includedir=/opt/UE_APP_OAM/include' 'LIBYANG_LIBS=-lyang -lpcre2-8' '--with-clippy=build-clippy/lib/clippy' '--enable-configfile-mask=0640' '--enable-logfile-mask=0640' '--enable-multipath=64' '--enable-user=toor4nsn' '--enable-group=root' '--enable-vty-group=root' '--enable-protobuf' '--disable-bgpd' '--disable-ripd' '--disable-ripngd' '--disable-ospfd' '--disable-ospf6d' '--disable-ldpd' '--disable-nhrpd' '--disable-eigrpd' '--disable-babeld' '--disable-isisd' '--disable-pimd' '--disable-pbrd' '--disable-fabricd' '--disable-vrrpd' '--disable-pathd' '--disable-capabilities' '--disable-doc' '--disable-mgmtd' '--disable-dev-build' 'AR=ar' 'LD=ld' 'RANLIB=ranlib' 'PKG_CONFIG_PATH=/workspace/Build/dusim/SDKROOT/lib64/pkgconfig:' 'CC=gcc -fstack-protector-all' 'CXX=g++ -std=gnu++2a -fstack-protector-all' 'PROTOBUF_C_CFLAGS=-I/workspace/Build/dusim/SDKROOT/lib64' 'PROTOBUF_C_LIBS=-L/workspace/Build/dusim/SDKROOT/lib -lprotobuf-c -lprotobuf -lz'

How to reproduce

In my environment, I have 2 dockers which are started using a docker compose, and I have 2 networks which are both available for each of my dockers. This is running on a Rocky Linux 8.10 host.

In my specific case, on docker 1 (dusim) I have a dhcp server , and docker 2 (rusim) retrieves some ip on its interface using dhclient. Once dhcp proc are done, BFD configuration is done on each interface of these 2 networks on both side.

dusim_ifconfig.log dusim_ip_route.log frr.log rusim_frr.log rusim_ifconfig.log rusim_ip_route.log frr.conf.log rusim_frr.conf.log dusim_bfd_interface_view.txt rusim_bfd_interface_view.txt

Expected behavior

BFD configuration is done successfully, and visible as up from FRR/VTYSH BFD view (show bfd peers)

Actual behavior

Bfd peer seen as down on vtysh's "show bfd peers" view.

There is an error in the traces, for instance:

• session-enable: specified interface eth1.295 (VRF default) doesn't exist

Additional context

No response

Checklist

• [x] I have searched the open issues for this bug.
• [x] I have not included sensitive information in this report.