nanog mailing list archives

Re: Out of ideas - Comcast issue BGP peering with Tata


From: Tom Beecher <beecher () beecher cc>
Date: Fri, 17 Nov 2023 11:04:35 -0500


Comcast has to be the one contacting them


This is the correct answer. It's pretty straight forward ; Comcast needs to
get with Tata, say "hey, I'm announcing prefix FOO to you, your LGs don't
look like you're accepting it. Can we figure out why?"

On Fri, Nov 17, 2023 at 10:43 AM jim deleskie <deleskie () gmail com> wrote:

I many years ago worked at Tata, responsible for their BGP, they are
giving you the right answer, Comcast has to be the one contacting them, as
then both sides can see what is being sent and received and can resolve
this issue.

-jim

On Fri, Nov 17, 2023 at 10:04 AM Jamie Chetta via NANOG <nanog () nanog org>
wrote:

I am out of ideas on how to get this fixed.  Long story short I am a
customer of Comcast and am advertising my own /24 block I own through
them.  Comcast of course BGP peers with multiple ISPs.  Other ISPs are
accepting my prefix just fine, except Tata.  This is causing random
destinations to drop connectivity if Comcast routes it through them.
Comcast has confirmed they are advertising my block to Tata and that the
RPKI is good, however when you check the Tata looking glass you can see
they’re not accepting it.



I’ve tried escalating within Comcast who refuses to contact Tata as
they’ve validated the issue is not on their end but they agree with my
assessment that Tata is not accepting the prefix for some reason.



I’ve tried multiple email for Tata support (below), but they all circle
around to a helpdesk who says I do not have a circuit with them so they
cannot help me.



Is there anyone from Tata willing to contact me off list to help sort
this out?  Or anyone with ideas on specifically why other ISPs are
accepting my route but not Tata?  It would be greatly appreciated.



Emails I’ve tried

Corporate  Helpdesk corp.helpdesk () tatacommunications com

Tata Communications IP Service Support( AS-6453)
IPServiceSupport () tatacommunications com

IPNOC (Tata Communications - AS6453) IPNOC () tatacommunications com

lg () as6453 net


Response from Tata:

“Acknowledge your email.



However, since you are not associated with TCL we would not be in a
position to help you on this.



Request you to contact comcast for the assistance that you are seeking
from us.”



Response from Comcast:

“This was sent back to me as not us. Basically, it’s not a RADB or RPKI
issue. This is being accepted and re-advertised to TATA but not being
accepted on their end. But another route that we checked off of that same
SUR is being advertised the same way and accepted by them off
pe12.350ecermak.il.ibone as an example of the TATA looking glass.  I would
suggest that you would probably need to work with other networks as to why
those that are specific ones are not accepting the block but as previously
mentioned it’s not a RADB or RPKI issue and as a result not a Comcast
issue.”



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