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VLan setup with a 3Com 3900 Switch and a Cisco 2621 Router (for a DMZ).

OK I need someon's help. I am trying to setup a DMZ.

I have a Cisco 2621 Router that is connected to the WAN link via interface FastEthernet 0/0.

I then have the interface FastEthernet 0/1 connected to my 192.168.1.X network.

I tried to get a Fast Ethernet Network Module for that Router but none was available so I went with the NM-1E Ethernet 10BaseT. That would be my 1/0 interface and it is going to my 192.168.2.X Network (DMZ).

My web server is on the DMZ and my SQL servers are on the other 192.168.1.X Network. When you try to serve up my site that needs data from my SQL server it is very slow. Now I think it has to do with the 10BaseT Network Module I have for my DMZ. Any ideas?

Now I am confident that is the reason it is so slow. So I am thinking of setting up VLans on my 3Com 3900 Switch and having them work with my Cisco 2621 router. Can someone help me set them up?

Thanks for any info you can give this Rookie.


Community Member

Re: VLan setup with a 3Com 3900 Switch and a Cisco 2621 Router (


On the 2621 FE0/1 you can set up a sub-interface for each vlan needed. So you want something like the following:

interface FastEthernet0/1.1

ip address

encapsulation dot1q 20

interface FastEthernet0/1.2

ip address

encapsulation dot1q 30

There is more information at:

Hope this helps,


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