Sup guys!
I got a fun question for ya. Lets say you are running layer 3 down to you access switches. Would you do L3 port-channels or L3 links using ECLB? Tell me what you would prefer to do, and why?
I have a tendency to want to be lazy so I'd probably just create routed links. With /31s you don't chew up too many IP addresses and just make sure my load-balancing algorithm is on point for the type of traffic I have. Plus you know your L2 domain stops hard at the access switch.
But I haven't spent a single day in an operational networking role, so I'm probably just talking out of my arse. ;P
If I were in an operational role though, I'd want to test this in a lab environment with each option, see how they recover from failures, etc. and weigh the pros/cons before making a definitive decision. That's due diligence.
I prefer /31s and ECMP. The main reason is my access switch will be uplinked to two agg/distro switches. If I use port channels then I need some kind of MLAG/VSS/VPC. Anyone doing that knows it is never a perfect solution. You have to deal with split-brain, and weird fail-over scenarios. With routed links everything just works.
-Otanx
routed ECMP is awesome but You need routed access ( never seen IRL outside of hyperscale) or some kind of VXLAN overlay including design of how North South traffic flows. And the default gateway + MLAG design. It's a new ballgame.
@LynK
What devices are you running at the access layer? Do they have the processing power to support multiple routed interfaces + the routing protocol, or will they get bogged down under the load?
I guess that doesn't truly answer your question. But if I was running something like large stacks of 3750's at the access layer with multiple stacks behind on L2, I'd be tempted to run port-channels. If my access layer was a 4500 series chassis switch with nothing behind it, I would be more likely to run multiple routed links.
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This is strictly a Hypothetical. Lets say 4500-x at the edge going to 7k/9k