Re: [Devmon] Ignore shutdown interfaces on Cisco switches

[Buchan M. <bg...@st...>]

On Tuesday, 29 December 2009 10:55:40 W.J.M. Nelis wrote:
> > On Monday, 26 October 2009 06:42:16 Colin Coe wrote:
> > > Hi all
> > >
> > > Apologies if this has been asked (and answered) in the past but google
> > > hasn't found me what I want.
> > >
> > > I've just setup Xymon and devmon and I'm monitoring Cisco switches
> > > among other devices. The problem is that switch interfaces that have
> > > no devices attached are causing the device to be shown in red.
> >
> > Firstly, I note that you should consider whether this should be the
> > correct
> > practice. E.g., in some environments I have worked in, the requirement
> > is that
> > unused ports be shut, or that unused ports that are not shut be in a
> > restricted VLAN, and are only allowed on some switch blades (and
> > configuration
> > management tools/processes in place to inform everyone of changes that
> > are
> > made).
> >
> > > Is
> > > there a way to prevent this?
> >
> > Sure, add exceptions for the interfaces, e.g.:
> >
> > DEVMON:except(if
> > _stat;ifName;na:Gi11/.*|Gi4/.*|ATM2/0.*|Gi5/46|GI7/1|ma0|CPP*)
> >
> > If you have a few specific interfaces that you want alarms on, you can
> > do it
> > the other way, e.g. with (if_stat;ifName;ao;Gi1/.*). Please see the
> > coverage
> > of the except option in the "USING" file for more detail.
> 
> I recently solved a similar problem, with the additional restraint that
> the "interesting interfaces" should be specified in the templates only,
> while the interfaces which are shutdown are listed only in the bb-hosts
> file.

Devmon ignores interfaces which are "shut", so you shouldn't need to exclude 
them in bb-hosts ...

> My final setup is as follows:
>  - in the templates, file exceptions, the exception "only" is used to
> select the interfaces of interest. The exception "ignore" is thus not used.
>  - in bb-hosts, for "all" tests, the "ignore" exception is used and the
> "only" exception is not used.

This is obviously not a generic solution, which means that you have to 
maintain local modifications to the templates (which is not what I want to  
encourage).

> Thus the devmon configuration in bb-hosts does not contain dependencies
> on tests, which is encoded only in the templates. The devmon
> configuration in bb-hosts does contain for each networking device the
> list of disabled interfaces. In my case, those lists are generated from
> a configuration database.

BTW, I've got a local hack to write some devmon test data to a database ... 
there are some minor issues with the feature I was wanting to create 
(effectively using devmon as part of a network discovery tool). Would this be 
of interest?

> For example:
>  in /opt/devmon/templates/cisco-6509/exceptions:
>     ifName : only   : Gi.+|Po.+
>  in /home/xymon/server/etc/bb-hosts:
>     DEVMON:model(cisco;6509),except(all;ifName;i:Gi5/1|Gi5/2)
> 
> The nett result is that the interesting interfaces which are not
> disabled are shown by devmon.

But, my 6509's and 6513's with Fa interfaces (some of which are connected to 
critical servers) and a 6513 with a PO (STM) interface - one of our two links 
to our upstream provider - would not benefit from something like this, so 
you'll have to maintain this locally, where you could have excluded all 
interfaces classes with a regex in your except option in bb-hosts.

So, it may work for you, but I would prefer to not recommend local changes to 
templates where they can easily be avoided, and that people push required 
changes to templates (and new ones) upstream.

Regards,
Buchan