Comments on: Unexpected results when port scanning AS/400 http://hatsecurity.com/2008/06/14/unexpected-results-when-port-scanning-as400-systems/ ../something for all Hats Thu, 06 Aug 2009 08:18:04 +0000 hourly 1 http://wordpress.org/?v=3.0 By: ohess fourhundred http://hatsecurity.com/2008/06/14/unexpected-results-when-port-scanning-as400-systems/comment-page-1/#comment-414 ohess fourhundred Tue, 16 Dec 2008 20:08:25 +0000 http://hatsecurity.com/?p=30#comment-414 OS/400 has this problem for years. I opened a ticket with IBM in the V4Rx days and it's still not resolved. At the they didn't know what nmap is, and in fact their front line OS/400 support technicians still don't know what nmap is. I port scanned a V6R1 system which caused a DoS of the TCP service. The system couldn't accept new connections, but existing TCP connections remained active. Anyways, the quick fix is not to reboot, but to simply issue these commands: endtcp strtcp I am surprised that the OS/400 controller you mentioned above rebooted the server. He should really learn the OS. OS/400 has this problem for years. I opened a ticket with IBM in the V4Rx days and it’s still not resolved. At the they didn’t know what nmap is, and in fact their front line OS/400 support technicians still don’t know what nmap is. I port scanned a V6R1 system which caused a DoS of the TCP service. The system couldn’t accept new connections, but existing TCP connections remained active. Anyways, the quick fix is not to reboot, but to simply issue these commands:
endtcp
strtcp

I am surprised that the OS/400 controller you mentioned above rebooted the server. He should really learn the OS.

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