Date: Thu, 20 Feb 2003 16:18:39 -0600 (CST) From: Joseph Noonan <jfn@msc.com> To: freebsd-questions@FreeBSD.ORG Subject: Bizarre Networking Problem Message-ID: <20030220155544.V84973@pcjfn.msc.com> In-Reply-To: <27.39e39215.2b869c70@aol.com> References: <27.39e39215.2b869c70@aol.com>
next in thread | previous in thread | raw e-mail | index | archive | help
I have a really weird networking issue on my firewall box. The machine in question has an ethernet facing a cisco facing the Internet and an ethernet facing the LAN plugged into a 3com 100Mbit switch. My LAN has all of the servers and most of the workstations sitting in the /24 that I've had for 10 years. Some of the newer workstations are now sitting on a /24 that I got from one of my providers when I filled up the old space. On xl0, the LAN ether, I simply added one of the new /24's to the interface with an ifconfig -alias and thought everything was good. And it was for users that only use the LAN for e-mail and www. But when I added some users that started messing around with 25MB pppts or 100MB .docs, the performance became pathetic, like in the single or low double digit kbps. The very same computer, can download a 100MB file from the 'net over a T1 faster than it can get a 50MB file off of my Samba based BSD file server. If I change the machines IP to one in the old /24 everything is fine again. Now it gets really weird. Today, one of my associates was investigating this problem and doing the experiments that document the above facts on two different machine. He called me and told me what he found. I logged into the firewall and started running tcpdump against the one address and also looking at the firewall logs to make sure I wasn't firewalling my own network. A few minutes later one of the users afflicted by this issue called to thank me for fixing the problem. I said eh? I haven't done anything other than look at the problem and I'm stumped. He says whatever, works great now! My associate confirmed this on another machine. Well, it is true, I *did* do something: I put xl0 into promiscuous mode. But why oh why is that fixing what should not even be a problem to begin with? Any klews cheerfully accepted (including hitting me with a clue-by-4 if I'm missing something obvious). -- Joseph F. Noonan Rigaku/MSC Inc. jfn@msc.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030220155544.V84973>