Edit: The issue came about because our machines did not have external IP address and so outgoing traffic was going through Cloud NAT, which was misconfigured (min connections per vm)
I am having issues with a GCP machine being able to connect to an external HTTP server. Below is a line from tcpdump
16:17:26.561616 IP 126.96.36.199 > 188.8.131.52.http: Flags [S], seq 1152634327, win 28400, options [mss1420,sackOK,TS val3415260604 ecr 0,nop,wscale 7], length 0 16:17:26.561736 IP 184.108.40.206 > 220.127.116.11: ICMP host 18.104.22.168 unreachable - admin prohibited filter, length 68 22.214.171.124 is a GCP gateway 126.96.36.199 is my machine on GCP 188.8.131.52 is the external server
How do I know which machine is enforcing the rule that blocks the connection attempt?