From owner-freebsd-questions Thu May 7 10:41:18 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA25288 for freebsd-questions-outgoing; Thu, 7 May 1998 10:41:18 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from gdi.uoregon.edu (gdi.uoregon.edu [128.223.170.30]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id KAA25268 for ; Thu, 7 May 1998 10:41:11 -0700 (PDT) (envelope-from dwhite@gdi.uoregon.edu) Received: from localhost (dwhite@localhost) by gdi.uoregon.edu (8.8.7/8.8.8) with SMTP id KAA23914; Thu, 7 May 1998 10:41:04 -0700 (PDT) (envelope-from dwhite@gdi.uoregon.edu) Date: Thu, 7 May 1998 10:41:04 -0700 (PDT) From: Doug White Reply-To: Doug White To: Clod Baldrick cc: freebsd-questions@FreeBSD.ORG Subject: Re: Bizarre routing problem In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 7 May 1998, Clod Baldrick wrote: > lancaster$ ping tomcat > PING tomcat (130.13.21.92): 56 data bytes > > tomcat# tcpdump -i ed2 host lancaster and not host corsair > tcpdump: listening on ed2 > 11:02:42.566674 lancaster > tomcat: icmp: echo request > 11:02:42.566746 tomcat > lancaster: icmp: echo reply > 11:02:42.626639 lancaster > tomcat: icmp: echo request > 11:02:42.626692 tomcat > lancaster: icmp: echo reply > 11:02:43.566685 lancaster > tomcat: icmp: echo request > 11:02:43.566749 tomcat > lancaster: icmp: echo reply > 11:02:43.626636 lancaster > tomcat: icmp: echo request > 11:02:43.626688 tomcat > lancaster: icmp: echo reply > 11:02:44.566655 lancaster > tomcat: icmp: echo request > 11:02:44.566717 tomcat > lancaster: icmp: echo reply > 11:02:44.626606 lancaster > tomcat: icmp: echo request > 11:02:44.626659 tomcat > lancaster: icmp: echo reply > 11:02:45.566578 lancaster > tomcat: icmp: echo request > 11:02:45.566641 tomcat > lancaster: icmp: echo reply > 11:02:45.626568 lancaster > tomcat: icmp: echo request > 11:02:45.626620 tomcat > lancaster: icmp: echo reply > ^C > 92 packets received by filter > 0 packets dropped by kernel > > If I read this right, packets from lancaster are successfully getting > through to tomcat, which is correctly sending out ICMP responses. But > these responses don't get through to lancaster. And when tomcat pings > lancaster, the ICMP echo requests don't get through either. That seems to > account for the symptoms we're seeing. Yeah, sounds like someone has a filter on blocking icmp. > That probably means that the problem is with Linux. So does anyone have > any suggestions before I go off and ask in a Linux forum? Make sure that there aren't any firewall rules blocking icmp. Doug White | University of Oregon Internet: dwhite@resnet.uoregon.edu | Residence Networking Assistant http://gladstone.uoregon.edu/~dwhite | Computer Science Major To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message