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Re: snmpconf Conflict Resolution Issues



Jon Saperia wrote:
> 
> on 06/22/2000 2:15 PM, Francis Reichmeyer (IPHighway MA) at
> FranR@iphighway.com wrote:
> 
> > Jon, quick question. What's an intentional conflict between policies?
> > Thanks,
> > -Fran
> 
> I do not recall what others might have meant at the meeting. In simple
> terms, a conflict is one where provisioned (downloaded) policies are sent to
> a device that have conflicting values for an object.


I made some comments at the interim in this area, but
it was to point out the need for explicit evaluation precedence.

There are conflicts that can be detected at load time:
  Policy 1: All interfaces with ifSpeed from 10MBit to 100MBit 
            get 'bronze' QoS
  Policy 2: All 100MBit interfaces connected to dept. WEB servers 
            gets 'gold' QoS

There are conflicts that can only be detected at run time:
  Policy 1: All interfaces with ifSpeed from 10MBit to 100MBit 
            get 'bronze' QoS
  Policy 2: The interface attached to the Engineering WEB server 
            gets 'gold' QoS

In each of these cases, policy 2 must have higher precedence.

This is no 'automatic' conflict resolution.
You need a real development environment with a real debug tool,
and some engineers who know what they're doing. 
Just moving the program to the device doesn't make the programming 
work go away.

> 
> Andrew pointed out, and he is correct that this is to be avoided. The place
> where it will happen is when one policy is intended as a policy to become
> effective in failure conditions and replace another policy. This is where
> the idea of policy groups and priority are helpful. For example if a policy
> evaluates to 'true' when there is a failure condition of some sort and it
> has a higher priority, then it would overwrite the other policy. Actually
> there would not be a conflict.
> 
> Hope this helps.
> 
> /jon

Andy