[c-nsp] Reaction to forwarding failure...

[rwcrowe at comcast.net]

I for one would love this feature. I see alot of designs where L3A and L3B are setup as you have shown or they are dual-homed to CoreA and CoreB. But as you said if a PFC or some forwarding engine fails you are stuck with process switching and your performance goes into the toilet.


--
rwcrowe at comcast.net


-------------- Original message -------------- 

> I had an idea and wondered how common this would 
> be and how much customers would like it. 
> 
> The idea is how to react on a known failure 
> type for a redundant design. 
> 
> Let's say you have this: 
> 
> COREA COREB 
> | | 
> L3A L3B 
> | | (HSRP) 
> Access layer switches 
> 
> 
> 
> Pretty typical design if you are not doing L3 all the way to 
> the access. Now let's say you have some form of hardware 
> forwarding failure on the L3A (l3 switch) switch. With the 
> failure there is a chance you punt the packet to process 
> level and overrun the CPU. Assume L3A is HSRP primary. 
> 
> What about if there were a configurable option that for 
> known failure conditions you could have all routing 
> disabled for the routing protocols and also have HSRP 
> disable itself? That way you would failover to the 
> redundant path both ingress/egress to the core. 
> 
> Clearly this doesn't apply to all designs. If you only 
> have a single path you would want that path to continue 
> to pass the traffic that it can. You could still reach 
> L3A from COREA by telnetting to the directly connected 
> ip address. 
> 
> Thoughts? 
> 
> Rodney 
> 
> 
> 
> 
> 
> 
> 
> 
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