Trunk a 2950 to a 3com Switch

[jarcna]

Hello everyone, I'm pretty new with working with Cisco switches. But here I go, I believe I understand how to trunk two seperate Cisco switches, my questions is: I have a 2950 on a network with multiple VLANs and I need a 3Com switch to connect to this 2950 and the devices on the 3Com join some of these different VLAN's. My problem is this 3Com switch is an unmanaged device. I can't get into it at all.(I don't think I can). So how can I make this stupid 3Com switch communicate with my Cisco switch. Does it just not work that way? Do I trunk a port on the Cisco (ie FE 0/24)
switchport mode trunk
And then do something else to the specific port and then the 3Com will just work??? Thanks for all your help.

 

[ADB100]

If you can't get into the 3Com switch (or it doesn't have any management) then you won't be able to use VLAN trunks. If its unmanaged does it even support VLAN trunks?

Andy

 

[jarcna]

Thanks for your help...I don't believe it can manage VLAN's.

 

[vipergg]

If its umanaged then it can only run within a single vlan and or subnet however you want to look at it thus you cannot trunk to a device like this . You need a new switch that supports trunking and vlans to be able to do this .

 

[jarcna]

vipergg....sorry I'm a little confused..if I can't trunk the switch to the 3Com how do I make it communicate?? How does the 3com know to use VLAN " "? Thanks...

 

[ADB100]

....sorry I'm a little confused..if I can't trunk the switch to the 3Com how do I make it communicate?? How does the 3com know to use VLAN " "? Thanks...

Quite simply the 3Com switch doesn't support VLAN's. All the ports are in the same broadcast domain (same VLAN) and you can't change this. If you need to use VLAN's on this switch then you will have to replace it with a switch (3Com or an other vendor) that supports VLAN's and 802.1q Trunking.

HTH

Andy

 

[vipergg]

What Andy said ..

 

[vipergg]

Best way to check is to get the 3com model number and go to their website and see what the switch is capable of doing . If it managable or not and whether it supports vlans and trunking . If it is manageable then you will have to figure out how to break in if you don't have the passwords also on their website somewhere.

 

[UnaBomber]

The 3com will drop any tagged frames, because they will be too big as far is it is concerned, which means any frames from any VLAN apart from the native one. So In theory you could change the native VLAN on the cisco to which ever VLAN you wanted the 3com to have access to.

Its messy but at least it should work, and allow you to design around your equipments shortcomings.



UnaBomber
ccnp mcse2k