Ugh! Just been doing some testing with PIM sparse mode and run up against what is probably a code issue.
The situation – two routers connected together over ethernet. R1 has ‘ip igmp join-group 230.0.0.1′ on its ethernet interface – this makes it a listener for that group. R2 is a PIM bootstrap router (BSR) and rendezvous point (RP). Now, I should be able to ping 230.0.0.1 from R2 and receive a response, but I wasn’t getting anything. Read the rest of this entry »
Just for reference really: I needed to have a static route whose presence depended on the IP reachability of a host. If the host wasn’t there, the static route should disappear, and default routing take over. Read the rest of this entry »
Just managed to screw up my terminal by going into the ‘Window settings’ dialogue box, and hitting ‘Use settings as default’ – while I was telnetted into something.
For some reason, the telnet session was taken as a default setting too. So every time I started terminal it tried to telnet immediately to the remote host (which wasn’t there).
The only way I could get a command-line session was either to do a CTRL-Z to put the telnet session into the background. The alternative was to switch on the remote host, open terminal, telnet to the remote host and then telnet back!
Fortunately, I found this very useful page and the instructions there fixed it:
http://kleeschulte.blogspot.com/2008/05/apple-regedit-changing-terminalapp.html
Well – just began my CCIE SP study in earnest today – after almost a year of procrastination!
I got a dedicated Ubuntu box, and run Dynamips there. GNS3 is running on my Mac, leaving the dedicated machine doing the hard work.
Interesting news from Cisco this morning: they’ve just launched the new ASR 9000 – an aggregation services router aimed at providing scalable video delivery, increased mobile backhaul capacity and carrier ethernet services at the edge.
For some reason, I never knew that you could trunk and use a sub-interface on the same port of a Catalyst 6500, so I’m recording it here for personal reference.
What I wanted to achieve was to connect two 7600 routers over an Ethernet pseudowire (E-Line, EoMPLS circuit, AToM circuit, Martini circuit – whatever it’s called these days). The reason I needed to do so was that the interveninig 6500 routers were only getting a default route via BGP from the 7600s. Read the rest of this entry »
Just read a really nice guide to exclusive configuration mode access in IOS, written by Joe Harris.
Its a useful way of stopping other people pulling the rug from under your feet (while you’re busy scratching your head about some route-map or other).
For some reason (and for quite a long time) policy routing seemed a bit of a scary subject. I’ve noticed other people don’t like it very much either, but it is actually not all that bad. Read the rest of this entry »
Just for personal reference really:
The ME3750 has several ways of setting the MTU: Read the rest of this entry »
