MLAG Setup, only one Link for now?

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I have just added a 450g2 to my environment. Ideally, i'd have more than 1 fiber strand going from this idf to the MDF where the 670s reside. Those 670's run vrrp. Each fiber uplink would go to an interface on one of the 670s. Right now, i only have 1 spare fiber strand, so i only have the switch connected to one of the 670s, can i go ahead and setup mlag on the new switch and then configure whatever else i need on the 670s?, or should i wait until i have another fiber strand available to be able to have 2 uplinks, one to each 670? 

It seems that when i setup mlag on the 670s, i can no longer ping or ssh into the new 450-g2 but when i delete the mlag and group sharing interface, then it all works again. 
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mavsx .

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Posted 1 week ago

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Carsten Buchenau

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Your scenario would be a full MLAG setup with one link failing - I don't see why this should not work. Did you configure the one link as link aggregation on BOTH sides, with the same lacp settings?

I would make sure that I have really everything set up as if 2 fibers would be available, including the port on the 2nd 670 as well as the 2nd port on the x450g2.

Question: When you say you have one fiber strand, do you mean 1 pair of fiber? In this case you could change to bidirectional SFPs, using only 1 single fiber for both Tx and Rx - and the 2nd single fiber for your 2nd MLAG link. Even for 10G these bidi-SFP+ don't really cost anything anymore...
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Patrick Voss, Employee

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Hello Mavsx,

if the new switch is acting as a MLAG client then you should not need any MLAG configuration. Just configure the LAG and keep one of the links down. The switch will forward everything through the active port. If the x670s are setup for MLAG then you would just need to enable the MLAG port on both sides and when the cable becomes available just plug it in.