3 Posts
0
1149
February 1st, 2022 08:00
DELL x Broadcom switch FEC LACP issue (CL74 x CL108)
Hello all!
We have two S5248F-ON connecting to two BES-53248 (details below). We are using 25G speed.
Dell Switch: S5248F-ON
OS Version: 10.5.2.7
Dell Switch side transceiver: W4GPP (AFBR-725TMZ-FT1): https://docs.broadcom.com/doc/pub_005171_DS_AFBR-725TMZ_2018_01_19
Broadcom Switch: BES-53248
OS Version (EFOS): 3.8.0.2
Broadcom Switch side transceiver (AFBR-725SMZ): https://docs.broadcom.com/doc/pub_005171_DS_AFBR_725SMZ_2017_09_28
We were only able to bring those links UP after setting FEC to CL74 (on DELL side). Talking to Broadcom, they said BES will only talk CL74. Ok here.
The issue is that LACP is not working on those uplinks. DELL support is insisting that transceiver W4GPP does not talk CL74 (only CL108, which BES cannot). Unfortunately no document was sent stating that the DELL transceiver cannot support CL74 (even though the Link is UP after setting DELL FEC to CL74, LACP will not work).
From dell switch side we cannot see LACP BPDUs coming from the BES switch. Dell is sending BPDUs. BES is sending and receiving BPDUs. So apparently DELL is having some issue in receiving info from BES.
DELL transceiver is AVAGO, same as BES transceiver. So both are also Broadcom. Only difference I see from transceivers is that BES support 100m and DELL's 50m. The rest is almost equal.
I can see from several S5248 documents that CL74 is a supported configuration.
Does anyone have a clue?
Kind regards,
Pedro
peterrock
3 Posts
0
February 10th, 2022 06:00
Hello Mauro!
Thank you for your reply. That was exactly what Broadcom support told us (to downgrade to 3.7.0.4).
They explained that in 3.8.0.2 they added the priority tag to protocol packets (LACP in this case). They told us that Cisco switches worked fine with this, but now that they saw this issue with DELL ones, there'll be probably a rollback in 3.9.
Best wishes,
Pedro
peterrock
3 Posts
0
February 2nd, 2022 06:00
Hello all!
UPDATE:
On a packet capture we see:
On BES, send and receive LACP BPDUs
On DELL, send but do not receive. Actually, the packets are being received (packet trace shows them being received) but not counted towards the interface counters as being discarded (but no discard or errors on the interface).
Regards,
Pedro
Mauro Felipe
1 Message
1
February 3rd, 2022 12:00
Hello,
Downgrade the firmware on BES and check if the port-channel is UP.
I was having the same problem and Broadcom support asked to change from version 3.8.0.2 to version 3.7.0.4 and it solved.
Regards,
Mauro