Date: Fri, 16 Jan 2009 06:09:24 GMT From: Jason Chambers <jchambers@ucla.edu> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/130605: Certain hardware produces "Network is unreachable" errors for scanning tools Message-ID: <200901160609.n0G69O6b038695@www.freebsd.org> Resent-Message-ID: <200901160610.n0G6A1d4068701@freefall.freebsd.org>
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>Number: 130605 >Category: kern >Synopsis: Certain hardware produces "Network is unreachable" errors for scanning tools >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Fri Jan 16 06:10:00 UTC 2009 >Closed-Date: >Last-Modified: >Originator: Jason Chambers >Release: 7.1 >Organization: UCLA >Environment: FreeBSD box 7.1-RELEASE-p2 FreeBSD 7.1-RELEASE-p2 #3: Thu Jan 15 21:39:37 PST 2009 user@box:/usr/obj/usr/src/sys/UCLA7-64 amd64 >Description: On certain hardware platforms FreeBSD has problems issuing multiple outbound requests as typically seen with network security auditing tools. The current hardware platform in question is a Dell PowerEdge SC1435. I have 4 of these servers and all exhibit the same symptoms. As an example, NMAP or Nessus fails to perform reconnaissance. Nessus does not produce much for errors; numerous "BIOCSRTIMEOUT: Invalid argument" pcap related error lines are found in the nessusd.dump log. The "scan" finishes within 6 seconds with the conclusion that all hosts are dead. The same Nessus build works without incident on other hardware platforms running the same version of FreeBSD. Using TCPDUMP I can see that requests are being sent on the network and the associated replies are being returned. Nmap is unable to scan a system because it immediately goes into a loop of the following: sendto in send_ip_packet: sendto(4, packet, 44, 0, xxx.xxx.xxx.xxx, 16) => Network is unreachable Offending packet: TCP xxx.xxx.xxx.xxx:55555 > xxx.xxx.xxx.xxx:80 S ttl=56 id=xxxx iplen=11264 seq=xxxx win=1024 <mss 1460> Sleeping 15 seconds then retrying sendto in send_ip_packet: sendto(4, packet, 44, 0, xxx.xxx.xxx.xxx, 16) => Network is unreachable Offending packet: TCP xxx.xxx.xxx.xxx:55555 > xxx.xxx.xxx.xxx:80 S ttl=56 id=xxxx iplen=11264 seq=xxxx win=1024 <mss 1460> Sleeping 60 seconds then retrying The same "Network is unreachable" messages appear if I attempt to ping a host while a Nessus scan is running. I found a PR from a long time ago (2006) that appears relevant but it was abandoned. Making updates to that PR does not kick off an email to the FreeBSD-bugs mailing list so I made the conclusion that it is not working with GNATS correctly and decided to open a new PR. http://www.freebsd.org/cgi/query-pr.cgi?pr=102741&cat= I tried using a different network controller (bge vs em) but this had no effect. I have dedicated one of these systems to troubleshooting this problem if anyone would like to provide pointers towards further debugging. Regards, --Jason >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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