Cisco WS-C2950G-24-EI configuration

[net buzz]

Hi!

I got a Cisco WS-C2950G-24-EI switch to integrate with a Linksys SRW2024 and something is unusual about the existing configuration.

VLANS do not appear in the running configuration but when a show vlan is executed all the vlans are seen.

The existing configuration is also working whereby users in different VLANs can communicate to a main server that has a VLAN card defined. (sub-interfaces)

Please see the attached configuration.

My questions are:

(1) Where have the VLANs been defined? Should it not have been defined as follows:

interface Vlan201

no ip address

no ip route-cache

shutdown

!

interface Vlan202

no ip address

no ip route-cache

shutdown

!

interface Vlan203

no ip address

no ip route-cache

shutdown

!

...etc

(2) Is the following configuration on the Linksys SRW2024 and Cisco 2950 correct?

     Linksys

• Ports that should be in a single VLAN (e.g 270, 271,...) should be in Access mode, untagged VLAN which is also the PVID (e.g 270, 271,...).
• The port that should be connected (uplink) to the Cisco 2950 should be in Trunk mode. The default management VLAN (default 1) is the untagged member  and PVID. All other VLANs are tagged members. The port will only sent and accept 802.1q tagged frames which  are  configured on this port. The switch will drop tagged frames with a  VLAN  ID which is not configured on this port.

    Cisco

     In the Cisco:

     interface FastEthernet0/1

     description TRUNK

     switchport trunk encapsulation dot1q

Will this work?

Thanks,

Alvin

[glen.grant · Accepted solution]

     Vlans will not show up in the running config if the switch is running in vtp server or client mode.  It will only show up if the switch is setup as transparent mode. 

1) Where have the VLANs been defined? Should it not have been defined as follows:

interface Vlan201

no ip address

no ip route-cache

shutdown

!

interface Vlan202

no ip address

no ip route-cache

shutdown

!

interface Vlan203

no ip address

no ip route-cache

shutdown

!

...etc

Quick is answer is no , you are trying to setup a L3 relationship when you create a SVI for the vlan . This switch is a L2 switch only so the only thing  a address is used for on this switch is to manage the switch. All L2 defined vlans are stored in the vlan.dat file.  Do not do as you have shown above it will do nothing . It is as simple as the following to create L2 vlans. You can only create vlans when the switch is setup as vtp server or transparent .

conf t

vlan x

exit

Most of the rest of your assumptions look correct but I haven't had any dealings with Linksys , we strictly use the Cisco Catalyst and Nexus lines.