3com 2928 (Link aggregation and stacking)

[wsaunders]

Hi,

I am looking for some help regarding the 3com Baseline 2928-SFP Plus switches. We currently have 4 of these switches and would like to set them up in the following configuration; 1 master switch at the top of the tree with the remaining 3 switches directly connected to the master switch.

There are 2 ethernet cables going from the master to each of the slave switches which we created dynamic link aggregations (LACP). The problem occurs when attempting to set up a stack link (IRF) over this aggregated link to each slave - the master and slave devices simply cannot detect each other.

The stack link will work with link aggregation disabled however. I apologise in advance if any of the terminology is incorrect as I am fairly new to configuring managed switches.

Any help would be greatly appreciated.

Thanks,

Will.

[Fred_Mancen_1]

Buddy, the Baseline switches does not support stacking features. The IRF feature is supported only by 4500G (IRF Lite; in the last available version) and 4800G.

This message was edited by Fred_Mancen on 2-5-10 @ 10:47 AM

[wsaunders]

Hi,

That's a little confusing as there is an IRF interface for the switches through the web interface, and instructions are included in the user manual for setting up stacking of some sort. Please take a look at page 43 onwards titled 'IRF configuration' http://www.3com.com/swd/jsp/user/result.jsp?selected=6&sort=effdt&sku=3CRBSG2893&order=desc . I understand that these switches do not have the stacking cables/ports of more expensive models, but do support stacking of some degree via ethernet - you are able to control the slave switches through the master switch web interface (which I have done).

It is the combination of stacking and link aggregation accross the same connection that I am struggling with.

Thanks,

Will.

[TooMeeK]

I'm facing exacly same problem. 2 identical switches, 2 SFP 1000BASE-LX modules per switch. IFR simply doesn't work, even with 1 single ethernet cable without LACP.

Link aggregation doesn't work too (only failover), I belive becouse they have to be configured as single switch (it means: IFR).

Device Name: 3CRBSG2893

Product Information: 3Com Baseline Switch 2928-SFP Plus Software Version Release 1101P10

For compare, when using single 3Com 3824 switch and 2x aggregated gigabit channel for 2 servers can reach ~1800Mbits with round-robin policy (Linux) without LACP. This is not possible for 2928-SFP, even on single device.

[Tiago Vieira]

Switch A 2952

Vlan1(default) 192.168.100.0
Vlan10 - 10.39.0.0

Vlan20- 192.192.192.0

Vlan1 interface - 192.168.100.18
Vlan 10 interface - 10.39.0.18
Vlan 20 interface - 192.192.192.18

Port 1/29 - have a cable connected to switch B
- Tagged to VLan 1,10,20
- Trunk


Switch B 2952
Vlan1(default) 192.168.100.0

Vlan10 - 10.39.0.0
Vlan20- 192.192.192.0

Vlan 1 interface - 192.168.100.19

Vlan 10 interface - 10.39.0.19
Vlan 20 interface - 192.192.192.19

Port 18/29 - have a cable connected to switch A
- Tagged to VLan 1,10,20
- Trunk

I try to setup Link aggregaton between the two switches choosing port 1/29 on switch A and ports 18/29 on switch B but dont work, ports become on standby and keeps the number "3" for inactive reason ( the port is not configured properly). What else i´m missing?

I setup both port manually to 1000Mb Full duplex.

I need ideas to continue setup those switches on kink aggregation.