Azure filtering IPv6 requests?

[humeipv6]

I've been noticing performance problems with MS-related traffic, like Teams logins and websites that make use of Azure's CDN.  After some investigation, it looks as though the Azure CDN will accept connections, but then the request times out.  For example:

$ curl -vk ecom-cdn.afd.azureedge.net

*   Trying [2620:1ec:bdf::51]:80...
* Connected to ecom-cdn.afd.azureedge.net (2620:1ec:bdf::51) port 80 (#0)
> GET / HTTP/1.1
> Host: ecom-cdn.afd.azureedge.net
> User-Agent: curl/7.88.1
> Accept: */*
>
* Recv failure: Connection reset by peer
* Closing connection 0
curl: (56) Recv failure: Connection reset by peer


This happens pretty consistently on all IPs in my Tunnelbroker /48.  It does NOT happen from my workplace, which has its own IPv6 block.

I know some ISPs have marked tunnelbroker blocks as hostile.  At this point I'm just curious if anyone else has noticed similar behaviour from MS.

[joestr1]

Yep, can confirm. Microsoft offerings are virtually unusable.

[jon47]

I know I'm late responding, but I had a similar (but possibly different) issue. Something is broken with MTU discovery, and the net result is that azure and microsoft servers often respond in weird ways, if they respond at all.

Check your MTU is correct:  in my case clamping it to fit in the limitations of PPPoE and my home broadband fibre to the cabinet fixed things, and MS servers sprang into life.

Jon