Trunking between Cisco 4006 and 3Com 3300

[fcfcfc]

I am trying to set up a trunk connection of 4 ports between a Cisco 4006 and a 3com 3300 switch.

I checked all the relevent ports individually, one on one and they connect fine. When I define a truck group on the 3com side and do the same on the cisco side, everything looks good, green lights etc but I can't get any communication across. I Tried many different options, non-negotiate, on, off etc....

Is there some kind of check list for connection parameters on the cisco side? The 3com side is pretty straight forward, not many options. Both switches support 802.1q protocol.

.....Bill

[osbauer]

Bill,

The first thing you need to check is that you are running software release 4.4(1) or greater. When trying to create a port channel all of the port, VLAN and trunk parameters must match otherwise the channel will never come up. When connecting to a non-Cisco device you will have to configure the port channel and the trunks manually using the following command: set port channel on. Your trunk settings should be nonegotiate and dot1q. You can either configure all of the trunks before adding the port channel or you can configure one of the ports after the channel is up and it will automatically configure all ports. If your still having problems refer to the following link: http://www.cisco.com/warp/public/793/lan_switching/6.html#tshoot

Regards,

Oscar Bauer

[Erick Bergquist]

Cisco Port Channeling (Fast EtherChannel) is Cisco propiertary and may not work with 3Com port/link aggregation. I haven't tested this myself personally so am not sure it works. I've heard of other people able to get FEC working with non-Cisco gear if they set to on (no auto stuff) but your milage may vary.

802.1Q alone should work fine between Cisco and 3Com. Just make sure the ports on both switches connecting to one another are in the same native VLAN. The native VLAN in 802.1q is not tagged. On the Cisco side, set trunk to on (no auto stuff).

Offhand, I can't recall if "trunking" on the 3Com means port/link aggregation or VLAN tagging.

HTH, Erick

[aessome]

Hello Oscar,

may be you will help me. I have a configuration prob. we have a 4006 with SupII, two L2 card in slot 2 and 3 . Avery L3 hat also 34 Fast eth Ports. I want to config the 4006 and connect 3 etage switch (3548XL EN)

please if you have a sample config for 4006 it will help me a lot. or explain me how to configure it

I will appreciate any help

Thanks

[osbauer]

Hello,

I am not to sure what it is exactly that your trying to do but I will send you the following configuration information. Maybe it will point you in the right direction.

The following link gives configuration information for the XL switch to a Cat6k.

http://www.cisco.com/warp/public/473/44.html

The following document gives you a more detailed configuration of the Cat4k.

http://www.cisco.com/warp/public/793/lan_switching/6.html

The following document will help you configure your 4232-l3 module.

http://www.cisco.com/warp/public/473/28.html

Hope this points you in the right direction.

Regards,

Oscar

[s.tecnico]

Hi Oscar this is Albert. Could you help me with this issue? Is pretty similar with the 3Com case:

I'm trying to configure trunking with FastEtherChannel (2 ports) between a cisco catalyst 2900 xl series and a HP Procurve 4108 gl where in the specifications says FEC is supported but I'm not able to do so:

The way that I configure in the cisco two ports to form a fastetherchannel is:

int fa0/23

speed 100

duplex full

port group 1

int fa0/24

speed 100

duplex full

port group 1

In the HP the way is something like that :

trunk c13-c14 trk3 FEC

interface c13

speed-duplex 100-full

no lacp

interface c14

speed-duplex 100-full

no lacp

If I show cdp nei:

cisco#sh cdp nei

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port ID

hp(0004ea-3dbFas 0/23 125 S HP 4108GL Trk3

only one port is working (fa0/24 is down and is already connected)

the keepalive is not configured

At the HP 4108, only one port has link once the FEC is working

hp# sh cdp nei

CDP neigbors information

Port Device ID | Platform Capability

---- ----------------------------- + ---------------------------- -----------

Trk3 cisco | cisco WS-C2924-XL B S

I have tried to configure the cisco 2900 as follows:

int fa0/23

speed 100

duplex full

port group 1

switchport trunk encapsulation dot1q

switchport mode trunk

int fa0/24

speed 100

duplex full

port group 1

switchport trunk encapsulation dot1q

switchport mode trunk

but the result was de same. I'm sure the spanning-tree is disable at both switches and there's only the default vlan defined and the single ports works fine .

Can you tell what is going wrong or how must I configure it to work properly?

Thanks it advance

Albert

[joaopedro]

Check to see if the native VLANs are the same.

[fsebera]

You may want to look at the spanning tree parameters - if the 3com/Cisco device cannot activate all port as 1 combined trunk, than spanning tree will block 3 of the 4 ports to prevent a spanning tree loop, thus leaving you with a single active link. Hope this helps

Frank