Hey John, Thus spake John Kristoff via NANOG (nanog@lists.nanog.org) on Mon, Nov 17, 2025 at 10:53:43AM -0600:
On Wed, 12 Nov 2025 16:14:10 -0600 John Kristoff <jtk@dataplane.org> wrote:
I'd be interested in hearing if people set a hostname on their BGP routers and send it to peers (internal and/or external).
I'm also interested in hearing if you see external peers sending it to you.
I know BIRD and FRR support this capability, but I"m not aware of others and I'm guessing it is relatively rare in practice?
Most of what I learned about usage was in response to this thread, but I had a few brief responses from others elsewhere. Awareness and interest in it remains lukewarm at best.
I soon after realized that ExaBGP supported this capability as well.
The original discussion and reaction (pro and con) to the feature is here:
<https://mailarchive.ietf.org/arch/search/?q=%22draft-walton-bgp-hostname-capability%22>
Also note, there is an IANA assignment for it (73).
<https://www.iana.org/assignments/capability-codes/capability-codes.xhtml>
I'm guessing this capability will just sort of live on forever, rarely used until, if ever, those software implementations decide they want to remove it.
I have to admit I didn't even know it existed. In our measurement/monitoring systems we do record the BGP router ID of every neighbor. This is handy as it should[*] be unique to an AS and can help with troubleshooting for where you may have multiple peering sessions to the same router, particularly across address-families. IMHO, adding a hostname field seems at best duplicative and probably is just another thing to be poorly maintained and go stale over time. Dale [*] that should is lower-case in RFC6286 section 2.1 ...huh