RFC 9234 (BGP roles) possible bug

[Ondrej Zajicek]

On Thu, May 11, 2023 at 03:06:48PM +0300, Mikhail Grishin wrote:
> Hi,
> 
> We ran BGP roles at 1000+ BGP sessions.
> About 0.5 - 1% of them affected by some issue. Probably all of them -
> Juniper with the old junos.
>
> At the same time, question to the stage 3) - why Bird gererate such message?
> + In the logs printed Error: Role mismatch (provider)

Hi

Yes, it is a bug in BIRD. When BGP capability option is parsed, the
capability structure is initialized with the proper default value, but
when there is no BGP capability option altogether (like in these case),
the capability structure is just zeroed. Unfortunately, RFC 9234 is the
only supported capability that has non-zero default value (0xff), zero
is 'provider'. Will fix that.

I am surprised that in 2023 there are still BGP routers not supporting /
sending capabilities :-) .

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."