Some people have told me they don't think a fat penguin really embodies the grace of Linux, which just tells me they have never seen an angry penguin charging at them in excess of 100mph. They'd be a lot more careful about what they say if they had. -- Linus Torvalds, announcing Linux v2.0

Top Ten Cisco IOS Tips – O’Reilly Media

Kwam net deze pagina tegen tijdens het inbouwen van mijn Cisco ASA in het netwerk;

Top Ten Cisco IOS Tips – O’Reilly Media.

Bevat een aantal nuttige tips, deze kende ik nog niet:

One of the classic mistakes (I know because I have done it myself a number of times) is to incorrectly update an access-list on an interface when you are connected to the device remotely. And suddenly, the Telnet connection is dropped to the router because of a forgotten list entry that would permit your incoming connection.

There is another way. When you are doing something tricky, you can use the following feature of the reload command, which causes the router to reboot in a certain number of minutes. For example, let’s tell the router to reboot in three minutes.

    MyRouter#reload in 3
        Reload scheduled in 3 minutes
    Proceed with reload? [confirm]y

Now, we have three minutes to do what we need to do. Let’s say we are applying an access-list to serial0.

    MyRouter#config terminal
    Enter configuration commands, one per line.  End with CNTL/Z.
    MyRouter(config)#interface serial0
    MyRouter(config-if)#ip access-group 110 in
    MyRouter(config-if)#^Z
    MyRouter#

We made the change and everything still works. (Well, at least our connection wasn’t dropped.) Now all we have to do cancel the impending reload with the following command:

    MyRouter#reload cancel

Or, if our access-list update did destroy our connection to the router, all we need to do is wait three minutes (plus the router’s reload time) before the router is back online. After the reload, the router uses the original saved configuration before our access-list change.

Erg handig dus!