Hello!
I have a Compaq Deskpro machine with Slackware 10.2 (updated packages, the original kernel of 10.2 - 2.4.31). Today I executed nmap (v. 3.93) on it in order to port scan my router. It showed the results, nothing unusual. But after a few seconds, the shell freezed and I lost any connection with it. I went to the other room and logged to the machine. First, I checked the logs - /var/log/messages and /var/log/syslog. There was no entry for this problem. I executed "ifconfig" and "route" on it, nothing strange. Everything was like the machine had never crashed, except that it had no connection on eth0. After a few restarts of rc.inet1, rc.inetd and rc.inet2 (which actually messed up with inetd), it went back to normal work, but I can't find any logical explanation of this problem in the logs. I will supply more info, if you demand.

Sorry for my awful English, it's not my native language. I asked in a few Bulgarian forums and mailing lists, but nobody could help me.

Thanks!

Georgi Hristozov

Hi, welcome to LQ and the Slacker-Forum :}

Your English is good enough, I understand you.

In terms of the nmap / eth0 problem .... are you sure
that it's actually the Linux box that has the problem?

I managed to take down a whole network once by
running nmap against a Allied Telesyn switch, it didn't
like that a bit, and wouldn't come straight until a physical
reboot of the switch occurred.


Cheers,
Tink

The box has a direct connection with crossover cable to the router. The router is running Windows XP SP2 and it hasn't got any special protections from portscans (like black holes). The both machines have Realtek RTL8139 NICs.

If it's XP, is firewalling for the port that the Linux box
connects to disabled? Which version of nmap are you
using, and you were obviously running it as root?


Cheers,
Tink

I'm running Nmap 3.93 as root

A few moments ago, a non-privileged user crashed the system. He tried to port scan other IP-s and it was OK, but he executed nmap on the router and the inet subsystem went down. I forgot to mention that the router has Sygate, but I will ASAP try to port scan it without firewall.

Perhaps you could connect the computer in question through a cross over to another computer (not the router computer) and then try to scan it. If the system doesn't crash when you scan the normal PC without the router, then the problem has something to do with the router itself.