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.
I think it should work, as once packet is inside the switch (pass the phy) it would not know if it original came in via copper or fiber or care. At same time, I doubt very much anyone has tested this, besides you soon maybe??
I might suggest hard coding the speed, especially on Fiber side, would be a very good idea.
Finally did some tests and now can confirm it is working. Speed NOT explicitly configured but you HAVE TO >>set interfaces xe-2/0/0 ether-options auto-negotiation<< explicitly and MIGHT need to set full-duplex on the remote end statically. Got a working chain of Cisco ASA 5500-X (GW)-(lag)-> QFX5100-VC -(lag)-> EX2300-C -(lag)-> QFX5100-VC -(lag)-> Cisco 3560E -> EX2300-C -> "Pinging Laptop".
set version 14.1X53-D42.3 <*> set interfaces ge-0/0/0 ether-options 802.3ad ae10 set interfaces xe-2/0/0 ether-options auto-negotiation
set interfaces xe-2/0/0 ether-options 802.3ad ae10
set interfaces ae10 description ex2300
set interfaces ae10 aggregated-ether-options lacp active
set interfaces ae10 aggregated-ether-options lacp periodic fast
set interfaces ae10 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae10 unit 0 family ethernet-switching vlan members 10-11
NOTE: I have to highly discourage a mixed fiber and copper channel of that kind (5100-VC) to the ASA, but the issue I think lies on ASA side as also mixed channel between ASA and 3560E does not work as intended (one link goes to suspended, mostly the copper link; with 3560E the switch creates an independent link (I)). With the QFX the lag works SOMETIMES, but as well one link goes to suspended/detached/defaulted. I had scenarios where both links were up but unplugging (especially the copper) links caused the lag to fail, i.e. to have some missing links again. I only used lag with lacp and the active end always being the QFX5100-VC.