LAG and switch configuration

[Graham Allan]

Funny, I see a similar question was just asked.

I'm trying, for the first time, to set up a LAG interface on 5.1B PK6 using two bcm interfaces. I believe I have the Tru64 config correct, with both interfaces unconfigured, then in /etc/inet.local:

lagconfig -c lag=lag0,key=1
lagconfig -p bcm0 key=1
lagconfig -p bcm1 key=1
ifconfig lag0 128.101.xxx.xxx netmask 255.255.254.0 up

and the lag0 interface comes up. But, no traffic, and very erratic (almost no) ping response.

I wonder what the switch config should be - I am assuming LAG == LACP, but I may be wrong? Switch is an HP Procurve 4108 with LACP configured on the ports. I tried both active and passive LACP but no joy - "show lacp" on the switch shows the interfaces up but no LACP peer. Should I have something else? I know LAG is a "subset" of 802.3ad, maybe the missing part is that Tru64 doesn't do the negotiation part of LACP? The switch will supports a "non protocol" trunk - worth trying?

All ports are set to auto-negotiate by the way, but it's unusual to use anything else for gigE ports...

Thanks for advice!

Graham

[Graham Allan]

It actually seems like I have a hardware problem! My test system is an ES40 with one DEGXA on each PCI bus. The one on the upper bus just registers errors ("netstat -i" output), and when I move it to the bottom bus it works fine.

"/sbin/hwmgr view hierarchy" extract:

1: platform AlphaServer ES40
2: cpu CPU0
3: cpu CPU1
4: cpu CPU2
5: cpu CPU3
9: bus pci1
10: connection pci1slot4
16: scsi_adapter itpsa0
17: scsi_bus scsi0
67: disk bus-0-targ-0-lun-0 dsk0
12: connection pci1slot5
75: network bcm2
14: connection pci1slot6
20: network bcm0
21: bus pci0
22: connection pci0slot1
34: graphics_controller comet0
24: connection pci0slot2
35: fibrechannel_adapter emx2
36: scsi_bus scsi2

Not sure if this is a documented limitation of DEGXA in ES40 model 1, or just a hardware fault in the PCI backplane. Now that I check, the DEGXA in our other ES40s is also on bus pci1, so I don't know if they simply don't work on pci0...

With both cards on the pci1 bus, the lag interface comes up. I still have the switch configured for LACP, and it doesn't show a trunk being negotiated, so I do still wonder if I should have a "non-protocol" trunk defined - but that does sound to me like the switch no longer uses 802.3ad at all...?

[Graham Allan]

Initial problem was a hardware issue - probably a bad pci backplane. Swapped cards and hard drive into a spare ES40 and all works.

Still curious about the optimum switch config.