ELRP Configuration - summitX-15.3.4.6-patch1-14.xos


When configuring ELRP, what if you include uplink ports in your VLAN statement, but then issue the disable- port exclusion command. Will excluding the uplink ports take precedence over them being added in the first place? Thanks in advance.

6 replies

Userlevel 1
hi ,

So elrp sends out elrp packets on the enabled port, but looks at all ports for received packets. It received it on say port 1, port 1 is not excluded from ports to disable so it disables port 1.

we exclude the uplink ports so it is not affecting other vlans that it is loop detected
Userlevel 6
This is the recommended way to configure ELRP. In an all EXTREME network it makes it easier to trace down where a loop is coming from. Even though the uplink is excluded from any action configured it will still log a loop and tell you which port it is ingressing and egressing out of.
Patrick Voss wrote:

This is the recommended way to configure ELRP. In an all EXTREME network it makes it easier to trace down where a loop is coming from. Even though the uplink is excluded from any action configured it will still log a loop and tell you which port it is ingressing and egressing out of.

Thanks. On some of our ELRP configs, there are some uplinks added to some vlans. With this being the case, it is going to disable those ports if there is a loop . With that being the case, I would like to disable those uplinks without having to search through the configs and remove those uplinks. I was wondering if I could run "configure elrp-client disable-port exclude xx" in Netsight on all my access switches and that would override any of those uplinks being added?
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Patrick Voss wrote:

This is the recommended way to configure ELRP. In an all EXTREME network it makes it easier to trace down where a loop is coming from. Even though the uplink is excluded from any action configured it will still log a loop and tell you which port it is ingressing and egressing out of.

correction - not disable the uplinks - should be remove those uplinks from the ELRP config.
Userlevel 6
Patrick Voss wrote:

This is the recommended way to configure ELRP. In an all EXTREME network it makes it easier to trace down where a loop is coming from. Even though the uplink is excluded from any action configured it will still log a loop and tell you which port it is ingressing and egressing out of.

Hello Dave,

Sorry for the confusion. That is what I was implying. Exclude the uplinks in the disable ports list and they will not be disabled if a loop is found on them but they will still log a loop on that port.
Userlevel 7
Hi,

if you add ELRP to the uplinks of all switches you will create a relatively high rate of flooded frames. You should limit ELRP on the uplinks to two switches in every L2 domain.

Thanks,
Erik

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