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I've been setting up a BSD server and every thing went fine. It still works fine except on my own IP address I cannot connect to my webserver at all and with SSH I can login but then as soon as I type a command it just times out. If I use a proxy/vpn/ssh tunnel/tor it works fine. I have no clue how to fix this whatsoever.

CakeSneer
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1 Answers1

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You're not giving very much information:

  • OpenBSD or FreeBSD server?

  • what OS is the machine you are working on?

  • does it happen from other machines that yours and can you give us the IP of the server?

  • is it a virtual server somewhere?

  • how are you connected?

  • what exactly do you mean by "can't connect to my webserver at all" (do you receive an RST packet in response to a SYN to server port 80, or does your browser just say "there is a problem", and does the page you are trying to load weigh more than about 1400 bytes)?

Anyway, it sounds very much like an MTU problem. You can:

  • do more research, using tcpdump to a file on both sides and checking what is happening to the packets (if it's not MTU at least you'll have data in a file that you can show)

  • test the MTU hypothesis by trying to debug your http connection, using telnet to port 80 and asking for different-sized pages

  • test the MTU hypothesis by using traceroute and ping with different-sized packets with the DF bit set

Law29
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  • It's an OpenBSD server. The problem only occurs on my own IP as soon as I use a proxy for my SSH it works fine. I can login to SSH but after typing one comment it throws me off. Again, only on my own IP. This problem occurred out of nowhere. – CakeSneer Apr 23 '16 at 07:55
  • I tried turning off PF as well but without success. – CakeSneer Apr 23 '16 at 07:59
  • Unless you have a very (too-) sophisticated PF config, any problems that occur after session establishment are not due to PF configuration. `tcpdump` will be the answer to that. – Law29 Apr 23 '16 at 08:02
  • http://pastebin.com/raw/dDQp8sUW : It kind of keeps going like that. However, my SSH client goes blank and closes the connection. – CakeSneer Apr 23 '16 at 08:13
  • Looks like they're just sending ACK to each other infinitely on the HttpD server. – CakeSneer Apr 23 '16 at 08:25
  • For ssh you should have some packets the other way too! What command line were you using to run tcpdump? You can run tcpdump on both sides and see if there are packets missing. Was your pastebin of tcpdump running on your server? It certainly looks as if there is an MTU problem somewhere. – Law29 Apr 23 '16 at 10:54