We have two servers on different VLANs and both are trying to access a specific http url. The page loads fine on one server, but not on the other one. The wireshark capture from non working server shows lot of TCP-keepalive messages followed by a RST. Can someone advise what could be wrong with the server, which is having issues connecting to the URL asked 27 Jun '16, 05:40  krmidhun |
One Answer:
One thing you can do is capture a trace on both servers, and compare the two to see the difference. If both servers are requesting data from the same URL, and one works while the other doesn't, you should get a trace from both, at the same time if you can, and compare them. Second, on the server that doesn't work, I'm assuming the keep-alives are coming from that server and it's also sending the RSTs. Is that correct? If so, you should look at your VLAN configuration (since both servers are coming from different VLANs) to see if anything is being blocked. Maybe there's a VACL blocking ports 80/443, if you're using default ports, or maybe even the IP of that server. So you compare the VLAN configs for both servers to look for differences that might be impacting the one that doesn't work. If you need more assistance, please include a trace file from the nonworking server, at minimum, but preferably from both servers that we can look at. answered 27 Jun '16, 08:31  jeantunis |
