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Eaps design

Eaps design

New Contributor II
In your opinion, how many nodes can I use in single domain, about 20 still will be ok? I knoiw that in theory eaps doesn't have limnitations.


Extreme Employee
Hi Pawel,
Here is one interesting discussing about EAPS design.

Best regards,

Contributor III
We try to keep ours to ten or less for reason number one... Our core which is 12 switches is the exception because several of the nodes are a pair of 8900's setting side by side... At 80 to 90 k mac tables with about 2500 active tag ids on 25 or 30 EAPS rings in the core we still get sub 150ms fail over... flaps hurt though

Extreme Employee
Pawel, EAPS does not impose a limitation in the number of nodes in a ring, but there are two factors that you should bear in mind:

  1. EAPS, being a ring topology, will survive to ONE failure. If a second failure occurs, you will lose connectivity. The larger the number of nodes (and links), the higher the probability of having two or more failures.
  2. When a failure is detected (or cleared) the Master switch will send a "Flush-FDB" message through the control vlan. When a Transit node receives this message it flushes its MAC table to relearn the new topology, and retransmits the message to the next switch in the ring. If you have a lot of switches in the ring, the time it takes for the ring to re-converge (that is, the time it takes for all the switches to flush their FDB and re-learn the topology) grows.
For me, the first factor is the most important, but the second should be considered if you need really fast convergence times.