Hello Com,
I came across this question few days ago while planning to increase link redundancy of a firewall.
There is a QFX5100 VC consisting of 2x 48S and 2x 48T. Location is splitted and one 48S and 48T pair reside in a rack plus a firewall.
The firewall is attached with 2x copper to the local 48T and the plan is to add two fiber links to the LAG which link to the opposite side 48S.
Unfortunately the firewalls only have 1g interfaces which is fine for them but on the 5100's I now would have to bundle the 48S ports using ge-x/x/x naming and the 48T ports using xe-x/x/x into the same LAG where all LAG members must be the same speed...
Is there anybody who can confirm this will work as intended? I already commited the configuration, mixing the interface names without an error but yet only the copper ports, autonegotiating 1G fullduplex, are connected and at the moment I cannot test it by myself..
In some other threads I read it might be required to strictly configure speed(1g) and (full)duplex for all ports of this LAG to make them work properly.. which of course would need to be done on the firewalls as well then.