Good afternoon, I finally found the source of most of my misery. It was a conceptronic wireless broadband router that some users were using as a switch in their office. I unplugged it at about 10:00AM and took it away :-) this morning, and since then I haven't had anyone calling in with a wrong DNS server allocation on their machine. Thanks alot for all the help and support!
On 11/02/2010, Markus A. Wipfler <[email protected]> wrote: > If your switch supports dhcp snooping, you can configure the port that > connects to your dhcp server as trusted port and all other ports as > untrusted (usually also your trunk ports should be configured as trusted, > however for this situation it' should not be necessary). Then enable > debugging of ip dhcp snooping events / packets (cisco specific command) and > you should be able to see which port your rogue DHCP server is connected to > (as well as its IP address IIRC). > > > Regards > > -- > Markus > > > > > > > > > > > > > On Feb 10, 2010, at 5:45 PM, Mark Tinka wrote: > >> On Wednesday 10 February 2010 03:31:26 am Okello Baldwin >> wrote: >> >>> Iif you have some managed switches and routers on this >>> network, just cross check the ip name-server command has >>> got the right DNS ip address. Possibly these switches or >>> routers have a different DNS ip assigned as the ip >>> name-server. You could start by disabling the command >>> using *no ip name-server* in global config mode. >> >> This has no bearing on transit traffic, only one traffic >> being generated by the router. >> >> Moreover, while routers can be used as DHCP servers, there >> is an abstraction between their internal DNS resolvers and >> those they can assign via DHCP. >> >> Cheers, >> >> Mark. >> _______________________________________________ >> LUG mailing list >> [email protected] >> http://kym.net/mailman/listinfo/lug >> %LUG is generously hosted by INFOCOM http://www.infocom.co.ug/ >> >> The above comments and data are owned by whoever posted them (including >> attachments if any). The List's Host is not responsible for them in any >> way. >> --------------------------------------- >> > > -- Emmanuel C. Sekyewa +256 782 199 202 _______________________________________________ LUG mailing list [email protected] http://kym.net/mailman/listinfo/lug %LUG is generously hosted by INFOCOM http://www.infocom.co.ug/ The above comments and data are owned by whoever posted them (including attachments if any). The List's Host is not responsible for them in any way. ---------------------------------------
