[AusNOG] Azure <-> Fastly connectivity issues in SYD?

[Paul Gear]

Hi all,

Happy Monday!

If we have any Fastly folks on the list, I'd appreciate your input on 
what appears to be a connectivity issue between Azure Australia East and 
Fastly, or a rate limiting problem somewhere behind Fastly's frontend IPs.

I've written up the problem at 
https://discuss.hashicorp.com/t/intermittent-connectivity-to-registry-terraform-io/22310, 
but the short version is that the IPv4 addresses 151.101.29.183 and 
151.101.30.49 are exhibiting intermittent SYN retransmissions in the TCP 
handshake from hosts in Azure Australia East.

These issues are not seen in our connectivity to numerous other external 
sites, nor are they seen from other locations (although it appears 
Fastly uses GeoDNS so when I attempt name resolution from my NBN 
connection I get BNE-based addresses rather than SYD-based ones).

Happy to discuss off-list by direct email, via the forum above, or 
wherever else is easiest for those who have the power to troubleshoot.

Thanks in advance,
Paul