[Cialug] Connection closed by remote host

[Nathan Stien]

I have a machine that isn't playing nice on the network today.  I
wonder if one of you savvy networking types might know what's going
wrong.

If I try to ssh to the machine, I get this:

  nathan at hugin:~$ ssh valis
  ssh_exchange_identification: Connection closed by remote host

Hmm.  So I nmap it to see what's going on:

  nathan at hugin:~$ sudo nmap valis

  Starting Nmap 4.20 ( http://insecure.org ) at 2008-01-18 14:58 CST
  Interesting ports on valis (10.0.0.5):
  Not shown: 1692 closed ports
  PORT     STATE SERVICE
  22/tcp   open  ssh
  80/tcp   open  http
  139/tcp  open  netbios-ssn
  445/tcp  open  microsoft-ds
  8080/tcp open  http-proxy

Curiouser and curiouser.  I try a browser for port 80 and get
"Connection to remote host is broken".  I try to go to port 8080, and
it connects, but never sends any data.  Same using either a browser or
just netcat.  Browsing to it with smb:// leads to an established, then
immediately broken connection.

I was able to get at ssh and port 8080 last time I tried, a couple days ago.

Does this scenario make sense to anyone out there?  I am baffled at
how this might happen.

- Nathan