Mlag configuration and isc link

[Gabriele_Stella]

Hello,
i'm going to configure an MLAG between two BD8806 and two cisco fiber channel switch.

At finally i will have something like this:

Actually the two BD are interconnected with two interface 10gb in lacp static.

Can i use this link to perform the ISC?
In this link i have a lot of vlan and STP per vlan stp, it's a problem? I need to create a stpd for ISC too?

I have read that in the ISC link i should not have any STP...

I need to perform a dedicated link for ISC??

Thank you,

Gabriele.

[Edward_Tsui]

ISC only exists on both core switches and on the inter-link. After you create the MLAG peer, make sure it is working properly before you add other member VLANs on both core switches and cisco.

I don't see any issue for your configuration but If you still worry about it, you may try it in lab first before implement to production.

[David_Choi]

Hi Gabriele,

As soon as creating mlag peer on an EXOS switch (even without having any MLAG ports), MAC learning mode of all ports in the switch will be changed to the SW mac learning mode so causing its FDB table to be flushed.
I think that is the reason of the recalculation of STP in your case and there might be service impact on clients continues until the fdb and associated arp tables are fully learned and populated.
This is an expected behavior on enabling MLAG peer, not a SW defect.

You should be cautious when creating MLAG peer in production.

[Edward_Tsui]

Did you create a new VLAN for ISC or reused existing VLAN for ISC? If you created a new VLAN for ISC and you see recalculation occurred, you may have enable auto-bind in STP configuration. Check the STP configuration to confirm.

[Gabriele_Stella]

3 weeks ago, i was configuring this mlag and when prompt the command

#create mlag peer core_b
#configure mlag peer core_b ipaddress 10.10.10.2

I had a recalculation of STP....
I don't know why..