Presumably nothing stops you spinning up an instance in Azure and doing pings/traceroutes yourself.

But perhaps you could be doing this from your own IPs towards <whomever>.

Have you configured your end in a manner that doesn't do MTU 1500 or that relies on PMTUD to function?

If yes, well perhaps start there... you're not on a solid foundation.

On Sat, Jun 29, 2024 at 7:46 AM John Alcock <john@alcock.org> wrote:

I have gotten pretty close to figuring out my issue with the Azure Cloud.  When I advertise my routes through one specific upstream provider, I have an issue. If I pull my routes from them, all works well.

I believe this is some type of MTU issue.  Could be filtering, but I doubt it.

Is there an Azure Looking glass that I can use to originate pings and traceroutes?  My googlefu is weak and I haven't found it yet.

With that information, I think I can help my upstream provider know where the problem lies.

John Acock

AS395437