we’re running a network with 3 racks, in every rack are 2 switches that are connected via mlag and then we created a ring between the 3 racks (yes, that’s not optimal, and we’ll move away from the ring as soon as we have the 4th rack)
So it looks like this:
Rack1#1 <-MLAG-> Rack1#2 <-Fiber-> Rack2#1 <-MLAG-> Rack2#2 <-Fiber-> Rack3#1 <-MLAG-> Rack3#2 <-Fiber back to-> Rack1#1
Switches are 7048T on 4.12.4
One day I ran a tcpdump on a machine connected to rack1#1 (our machines are always connected to both switches in a rack, but active-passive) and saw ‘normal’ (not multicast or so) tcp traffic between two machines that are connected to rack3#1 and rack3#2 (but only traffic from machineX to machineY, didn’t saw traffic from Y to X)
After clearing the MAC table with “clear mac address-table dynamic” everything went back to normal.
So, now a couple of questions
1) What was going wrong there? I was kinda lost where I could look & how to debug this issue. Can I analyze what the switch is doing with a packet? If it’s broadcasting the packages, and if yes, why it does that? =)
2) in the MAC address-table I see an entry with 0000.0000.0000 as mac address and a high amount of moves, do I need to worry about this? Normally this means that the address isn’t known yet by the switch, doesn’t it? In a stable network, should that entry show up at all? For me it’s “hopping” a lot on various interfaces
3) Could that be a firmware issue? I realized that we’re not running the minimum recommended version…
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