[mrtg] Multi target question

[Daniel McDonald]

On 7/17/12 2:35 PM, "Henrik Schack" <henrik at schack.dk> wrote:

> Hi
> I'm not sure I understand the multi target syntax correctly.
> 
> Here is what I'm trying to do.
> 
> I need to graph in/out trafic on a firewall network card
> My Target looks like this, and is working
> Target[mpls]: 
> 1.3.6.1.2.1.2.2.1.12.13&.1.3.6.1.2.1.2.2.1.17.13:xxxxxxxx at 10.75.76.2:
> 
> However there is a failover firewall with this target : Target[mpls]:
> 1.3.6.1.2.1.2.2.1.12.13&.1.3.6.1.2.1.2.2.1.17.13:xxxxxxxx at 10.75.76.3:
> 
> I would like only one graph, not having to care about when/if there is
> failover from one firewall to the other.
> 
> Could I achieve this with a target like this :
> 
> Target[mpls]: 
> 1.3.6.1.2.1.2.2.1.12.13&.1.3.6.1.2.1.2.2.1.17.13:xxxxxxxx at 10.75.76.2:
> + 1.3.6.1.2.1.2.2.1.12.13&.1.3.6.1.2.1.2.2.1.17.13:xxxxxxxx at 10.75.76.3:

Yes, however with snmpv1 there will be a significant number of counter
roll-overs.  If both interfaces roll over in the same interval you will get
garbage in your graph.

I would recommend that you monitor both interfaces separately, then use a
front-end like routers2.cgi to create a combined graph.
> 
> Or am I completely misunderstanding the concept of multi targets ?
> 

-- 
Daniel J McDonald, CCIE # 2495, CISSP # 78281