Assume IP Transit A and IP Transit B. Ingesting routes from both.
You are ingesting routes from both or both the Transit providers are accepting your advertised prefixes?
Ingesting routes from both Transit providers and both are accepting the advertised prefixes.
Transit B has a path failure but still advertises routes as preferable.
If you can be more clear to avoid assumptions. Are you saying Transit B is still advertising prefixes towards you and you are preferring them because of your routing policy or you are advertising prefixes outwards to Transit B and they are onwards advertising them and this is still seen as the best path by the rest of the internet?
There were path failures to Amazon and IBM Cloud that failed within the Transit provider. Traces in both directions failed within the Transit provider. The policy preferred the routes via Transit B for Amazon and IBM Cloud. Not necessarily the rest of the Internet.
They should stop advertising those routes but don’t.
If a path breaks completely and routes are being advertised over that path that would be interesting to see. If the path is “broken” as in congested that is different.
That is what I was noticing, the path was broken but the routes were still being advertises over that path.
How does a person fix this cock up??? There should be an easier way than dropping Transit B until they fix their path.
More detail would help but if you are saying prefixes are being advertised across a path that is truly broken that is a cock up.
We agree on that. My opinion is that its someone playing silly buggers with peering. Its intermittent but it happened for 20 minutes last night. Have seen it happen twice last year.
To answer your first question, there are someones on this list that have enable on the large African transit providers that can probably help if the cock up is there or those someones will know someones at upstreams to get them to help
Most tickets are dealt with as an immediate and visual fault but asking about root causation meets with a brick wall or some BS template response that is irrational in the context of the fault. Like the submarine cable owners of 5 cables haven't explained how there is a single point of failure for the whole continent of Africa 250km off the Cote d'Ivoire. I assume that the Transit provider advertises prefixes to the cloud providers regardless of having an internal fault as the route metric is the path between the two and not the full downstream path within the Transit provider?