Active/Active ECMP

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Active/Active ECMP

L3 Networker

I have two Palo Alto 5250s running in my core network as a core firewall for all campus and datacetner traffic. They are running active/active. I have layer 3 routing south bound to two cat9500s not in VSS. So I am running HSRP on each 9500 alternating vlans to utilize them both. All 4 units are running OSPF to advertise loopbacks and iBGP is used to carry routes. The 9500s are setup for ECMP and so are the Palo Altos. I feel like there is some weird traffic issues with this, Should the Palo Altos even be setup with ECMP? If so should I be using the symetrical return option? Would having ECMP on the Cat9500s be enough to achieve load sharing/balancing over each layer 3 link to each Palo Alto? Each cat 9500 has a layer 3 link to each Palo Alto. And yes before people tell me Active/Active is not a good idea I cant see why not when my network is symetrical. 


I think we are just making recomendations based on lessons learned the hard way.  For me, HSRP is never a preferred solution.  I will only used it if forced to by some crazy Layer 2 limitation being imposed on me.  You do you man!

I was just trying to understand the question of why do I think the standby node would receive traffic. 

Dynamic routing and HSRP "can" lead to a very bad day.


Here is some reading.  Old but relevant.  For me, HSRP = too much headache.  We need to move beyond these Layer 2 limitations.  We have the routing protocols, "we can rebuild him... we have the technology..."  HAHA!


Hope this helps.

Read it. Labbed it. It works. But "routing" doesn't solve LAN side requirements for hosts all the time. Not every corporation is running nexus as their core, not every corporation is stacking or using VSS. "Routing" doesnt solve a gateway problem. 

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