Hi,
I would like to summarize how I see the problem as perhaps I am missing something important.
You said that your Cat2924XL vere configured mostly default which means all ports static access, vlan 1, ie. they send untagged packets. They can receive from access ports (untagged) or trunk ports,but only untagged vlan, which is native vlan (vlan 1 by default). From what I know about Alvarion Breeze
Access products these can send and receive trunk (ie. tagged), access (untagged) or hybrid (both). The
choice is done by configuration, ie. static. Cisco can do static or dynamic (by DTP). Cat2924XL does not
support DTP (ie. static only), DTP packets can be disabled with Cat3550 (switchport nonegotiate).
Question number 1: If all the traffic was on Cisco side within vlan 1 (assuming all cat2924 at default),
who did the vlan assignment and vlan separation? (I assume you have more than 1 vlan connected).
Possibilities: Either not all Cat2924XL were at default or the vlan tagging and untagging was made
completely by Alvarion, or there is another communication device I am not aware of.
Now we add (substitute?) Cat3550. These seem to be a bit different. If the communication is to be untagged
they need to have switchport mode access set for the untagged packets (access) or switchport mode trunk &
switchport trunk enc dot1q for untagged packets from native vlan (vlan 1) if this comes via trunk - all this was tested for cisco environment. We have tried both options with no success.
Question number 2: Are all connections to cisco (ie. parameters at Alvarion) set identically? If no, we need to find harmonizing settings at cisco (out of the above two). If yes, what can still make a difference in behaviour as for Cat2924XL and Cat3550? DTP, VTP and PAgP are Cisco proprietary and should make no difference as the other side do not understand anyway. STP is a candidate.
Question number 3: Which STP type/mode run Alvarion (if any)? Cat2924XL run PVST with 12.0(5.2)XU which is Cisco propritary at that time Cat3550 runs PVST+ with Cisco proprietary extensions. There are certain restrictions when configuring dot1q trunk to be standard compliant but my view is that most likely this will work without a problem.
What else? I have noticed that interfaces at Cat2924XL and Cat3550 show different speed and duplex settings. From what I have read about Alvarion their units can adjust both settings according other side, but I know only very little about Alvarion. You have said you have all 10Mbps and half duplex. Is it worth checking to
set "speed 100" and "duplex full" under fa interfaces with Cat3550? I will leave the decision with you.
What else? I do not know how you have tested the suggested configurations. Provided you have changed one box (Cat2924XL) for another (cat3550) it is worth to wait a while to enable arp timeouts etc. or even to power down/up the other side (Alvarion) if possible.
Are there any error messages, warnings, etc produced during tests with Cat3550?
Anything else to worth mentioning. Any comments to my thoughts?
One last question: what was the reason you increased mtu for exactly 1528 (any reference by Alvarion)?
I am quite sure both units should interoperate. Unfortunately I have no Alvarion locally available to test.
Any feedback would be appreciated.
Best regards,
Antonin
