Sounds like an attempt at a man in the middle attack, where an infected host attempts to act as the gateway to see all the network traffic, analyze it, then forward it to the real gateway. Definitely not a good thing.
Chuck -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Wyatt Mattias Gyllenvarg Sent: Thursday, October 16, 2008 6:27 AM To: Ozgur Guler; [email protected] Subject: Re: [c-nsp] %SW_MATM-4-MACFLAP_NOTIF Hi all We have seen 3 instances of this the last days where a host (probably infected with a virus) has been broadcasting the mac of the local GW. Effectivly switching alla outbound traffic too his port. Fix has been too shutdown the offending port. So far this has only effected older setups. //Mattias Gyllenvarg 2008/10/16 Ozgur Guler <[EMAIL PROTECTED]>: > > "no mac address-table notification mac-move" might help. > > > > --- On Thu, 16/10/08, Jimmy Halim <[EMAIL PROTECTED]> wrote: > From: Jimmy Halim <[EMAIL PROTECTED]> > Subject: [c-nsp] %SW_MATM-4-MACFLAP_NOTIF > To: [email protected] > Date: Thursday, 16 October, 2008, 7:51 AM > > Hi guys, > > Recently I am getting the following log messages every 2 mins on the 3750 > switch. > > Oct 16 06:45:50 UTC: %SW_MATM-4-MACFLAP_NOTIF: Host 0017.cbb3.08fc in vlan > 403 is flapping between port Fa1/0/3 and port Gi1/0/1 > Oct 16 06:45:50 UTC: %SW_MATM-4-MACFLAP_NOTIF: Host 0017.cbb3.08fc in vlan > 402 is flapping between port Fa1/0/2 and port Gi1/0/1 > Oct 16 06:46:43 UTC: %SW_MATM-4-MACFLAP_NOTIF: Host 0017.cbb3.08fc in vlan > 402 is flapping between port Fa1/0/2 and port Gi1/0/1 > > This is non service impacting so far. However, I would like to know whether > we can disable this logging or not. Anyone has any suggestions? > > Many Thanks, > Jimmy > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
