The answer to the last question of the day “By default, what versions of updates does RIP send and receive?” is that RIP sends v1 and receives v1 and v2 by default. RIP v1 is able to process RIP v2 updates by simply ignoring the v2 specific fields.
Here is the output of a “show ip protocol” command with a default RIP setup. Notice the bold part where it shows what versions are being sent and received.
Router#show ip prot
Routing Protocol is “rip”
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Sending updates every 30 seconds, next due in 8 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Redistributing: rip
Default version control: send version 1, receive any version Interface Send Recv Triggered RIP Key-chain
FastEthernet0/0 1 1 2
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
2.0.0.0
Routing Information Sources:
Gateway Distance Last Update
2.0.0.1 120 00:00:23
Distance: (default is 120)
If you want to prevent RIP v1 from processing v2 updates, issue the “version 1″ command under the routing process. That will limit RIP to only sending and receiving v1 updates.
I ran across an article quite a while back talking about being to move from the current running config to another configurations without a switch/router reload. This can definitely be a big time/bacon saver at work and in your lab. The command used is…
Router#configure replace (config location)
So if you wanted to revert back to the start config, you would enter “configure replace nvram:startup-config”. But you could also replace the running config with a config file on the bootflash or from a TFTP server. There are plenty of options.
If you are thinking that you could just do a “copy start run” command, that doesn’t quite do it. What that will do is add all of the start config commands to your running config. But it won’t remove any commands from the running config. So it’s like it melds the two together.
Personally, I like using this in my home lab. If any of you have 2600 series routers, you know how long they take to reboot. I saw one blogger joke that they take 2600 seconds to reload. It’s not quite that bad, but it feels that way some times. Using this command, you can forgo the reboot and get back to a clean config in not much time at all. Of course this won’t do the trick in every situation. Some things require a reboot in order to reset. But it can be a nice option in the toolbox.
Here is a link to the article if you’d like to take a look for yourself.
