On Tue, 16 Aug 2005, David wrote: > I have a Cisco 800 router managed by powertel (don't ask!) which failed > mysteriously recently, apparently "caused" by an Ubuntu box. When > Ubuntu was disconnected, the cisco came back to life and worked normally. > Has anyone run into this before: > > Cisco -> switch -> Ubuntu warty > -> several Macintosh > -> 3 x Debian Sarge > -> Windows XP (powertel guy's testing laptop) > > I could ping around my LAN, including Ubuntu, but the cisco was not > responding from either the net, or my lan. I was getting a mixture of > unreachable messages, with the occassional 3 second ping response (about > one in twenty). > > The whole problem went away after unplugging/rebooting/reconnecting Ubuntu > and hasn't recurred! The nice powertel man suggested a network card > hardware problem in Ubuntu - but why would that lock up their cisco?
The Cisco device would block the bad port if it detects a problem. You could have had some kind of layer 2 conflict or problem with the NIC in the Ubuntu box which caused the Cisco box to go "Woah, there's a problem here, I am NOT going to pass traffic from this port/MAC address". It could also be a duplex/speed mismatch, especially if there are auto-negotiating devices from different vendors present in the mix. If the problem is not duplicable, it's really difficult to diagnose properly. DaZZa -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
