[frr 8.5.1] orphan routes with bgp suppress-fib-pending #15626
Description
Description
On FRR 8.5.1, one router setup bgp sessions with four neighbors, to announce / withdraw same routes from all four neighbors, there are orphan routes left after withdraw all routes.
Version
str3-7260cx3-acs-14# show ver
FRRouting 8.5.1 (str3-7260cx3-acs-14) on Linux(5.10.0-23-2-amd64).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
configured with:
'--build=x86_64-linux-gnu' '--prefix=/usr' '--includedir=${prefix}/include' '--mandir=${prefix}/share/man' '--infodir=${prefix}/share/info' '--sysconfdir=/etc' '--localstatedir=/var' '--disable-option-checking' '--disable-silent-rules' '--libdir=${prefix}/lib/x86_64-linux-gnu' '--libexecdir=${prefix}/lib/x86_64-linux-gnu' '--disable-maintainer-mode' '--localstatedir=/var/run/frr' '--sbindir=/usr/lib/frr' '--sysconfdir=/etc/frr' '--with-vtysh-pager=/usr/bin/pager' '--libdir=/usr/lib/x86_64-linux-gnu/frr' '--with-moduledir=/usr/lib/x86_64-linux-gnu/frr/modules' '--disable-dependency-tracking' '--disable-rpki' '--disable-scripting' '--enable-pim6d' '--with-libpam' '--enable-doc' '--enable-doc-html' '--enable-snmp' '--enable-fpm' '--disable-protobuf' '--disable-zeromq' '--enable-ospfapi' '--enable-bgp-vnc' '--enable-multipath=256' '--enable-user=frr' '--enable-group=frr' '--enable-vty-group=frrvty' '--enable-configfile-mask=0640' '--enable-logfile-mask=0640' 'build_alias=x86_64-linux-gnu' 'PYTHON=python3'
How to reproduce
Set up a topology with 4 upstream and one down stream peers in a different ASN. Have all 4 upstream peers advertise / withdraw the same 50 routes to the device.
Then, check the advertised to for the down stream peer, some orphan routes lefted.
with this config disabled, the issue is gone.
bgp suppress-fib-pending
Expected behavior
after announce / withdraw from upstream peers, no routes advertised to downstream peer.
Actual behavior
some orphan routes left, and still advertised to down stream peer. and if check from received routes, there is nothing.
Additional context
No response
Checklist
- I have searched the open issues for this bug.
- I have not included sensitive information in this report.