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Trunking 4000m and 1800-24g

Occasional Visitor

Trunking 4000m and 1800-24g


I'm trying to trunk 4 ports between a procurve 4000m and an 1800-24g.
As far as I can tell, the 4000m does not support LACP, so I'm trying to use the generically labeled "Trunking" feature on the 1800-24g.
What does this "Trunking" on the 1800-24g correspond to?
The 4000m supports an equally generic "Trunk", as well as "SA-Trunk" and "FEC".
The last option, Fast-Etherchannel is what I had assumed the 1800-24g was using, but it doesn't work, and I can't find any information confirming this.
I've tried all combinations, but have had no success in establishing a link between the two switches. Is there any detailed information on these options, or is there some other setting I've neglected to set up?
Ports on both sides of the switch are set up to use the same VLAN, and will establish a traversable link when non-trunked ports are connected.
Occasional Visitor

Re: Trunking 4000m and 1800-24g

I'm replying to my own message, as I seem to have figured out the proper configuration to make this setup work. One "solution" I hit upon, which worked in all cases except it was flaky with the redundant CARP address on my firewalls: turn on LACP on the ports 1800 side, and turn the SA-Trunk option on the ports on the 4000m side. This was a sub optimal solution, however, as noted above.
The correct solution required that:
1)Spanning tree was turned OFF on the 4000m
2)The trunk on the 4000m was set to FEC
3)The trunk port was set to TAGGED in the VLAN menu
4)The ports on the 1800 side were NOT set to LACP, but were put in a trunk group
5)In the "VLAN Port Config", the trunk on the 1800 side was set to "Ingress filtering enabled", packet type was set to "Tagged only", and PVID was set to "None".

Once the switches were set up as above, I could instantly access devices on the other switch, but it took about a minute before I could ping, telnet into or reach the web interface of the 4000m from the 1800 side.

Hopefully this helps someone else