Re: RIP passive interface command not showing up in the config

From: Christian Zeng (christian@zengl.net)
Date: Thu Dec 20 2007 - 17:34:18 ART


Hi,

* keith tokash wrote:
> I don't know why I went with "default passive-int default" the first time;
> I've never used that command before. Now I'm curious as to what it actually
> accomplishes.

'default' in front of most of the config commands resets the command to
its factory default setting (what is listed under the 'default' section
at each command in the command reference, or simplified to what gets set
when the router starts without a startup config). For

default passive-interface default

you are telling the router to revert to the default setting for
passive-interface, which is having all interfaces sending out routing
informations - effectively also deleting all 'no passive-i <interface>'
statements ('no passive-i default' does the same, afaik).

After your sequence of commands, nothing showed up in the running
config, since the

no passive-interface Ethernet0/0

was not preceded by the correct 'passive-i default'; the command had no
effect, because all interfaces were already not passive.

The default command can be very handy and it can be a better solution
when you want to start over with a complete config section or dont know
the defaults for a specific command, for example

(config)# default interface Fa0/0

resets all interface level settings under Fa0/0 to default

(config)# default logging trap

resets logging level for trap logging to default (5)

I got very used to the first example in real life on IOS switches.

Beware of some side-effects, like

(IOS 12.3, booted with no startup config)
Router(config)#do sh run | i subne
ip subnet-zero
Router(config)#default ip subnet-zero
Router(config)#do sh run | i subne
no ip subnet-zero

Which is interesting - since IOS 12.0 this is a config default and even
listed as such (12.4 doesnt even list it anymore in a fresh config), but
at least on my version (12.3.20), it gets disabled.

Hope this helps,

Christian



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