To add some more detail here. The root cause of the this issue was the use of a BGP attribute reserved for development in the VNC code[1]. The original intent was to disable use of this attribute by VNC[1] and FRR in production, but this didn't happen. My apologies for this. A proper fix has been submitted for all active releases and is undergoing testing. For those who are interested, release specific PRs can be found at [3]. Lou [3] https://github.com/FRRouting/frr/pulls On 1/7/2019 1:31 PM, Quentin Young wrote:
Hello operators,
This morning some users running FRR BGP noticed that their sessions were flapping. Investigation revealed that this was caused by an experiment being run by SwiNOG [0] which was triggering an undesired code path in FRR. Specifically, FRR uses attribute type 0xFF as the attribute code for VNC [1]. This code was intended to be turned off by default, but our current published builds [2] have it turned on. Consequently, bgpd attempts to parse the received attribute as a VNC attribute and fails, triggering a session reset.
We have a patch in testing now and expect to have new build artifacts published shortly. Additionally, we have contacted the experiment operators and requested a pause in the experiment while we handle this issue.
Thank you to the operators that notified us this morning!
- FRR maintainer team
[0] http://lists.swinog.ch/public/swinog/2018-December/007110.html [1] http://docs.frrouting.org/en/latest/vnc.html [2] https://github.com/FRRouting/frr/releases _______________________________________________ frog mailing list frog@lists.frrouting.org https://lists.frrouting.org/listinfo/frog