Cascade L2 switch to L3 switch

[Damodar Nagar]

Hi,

Actually our current L2 switch (2950) port full due to we want to cascade one more switch for extend port. but we have L3(cisco3750) switch.

so please give suggestion can we cascade L2 and L3 switch.

If yes please provide configuration commands.

Thanks in advanced

[ngthen]

Do you have a need for VLANs on the second switch?  Are you using them on the 3750?  If so are you using the Cisco VLAN database?  There are a few ways to add the second switch but the port configuration will depend on what you currently have configured on the 3750.

[Jon Marshall]

Damodarnagar wrote:
Hi,
Actually our current L2 switch (2950) port full due to we want to cascade one more switch for extend port. but we have L3(cisco3750) switch.
so please give suggestion can we cascade L2 and L3 switch.
If yes please provide configuration commands.
Thanks in advanced

Yes you can do this. You don't say whether the 3750 is already in use or not. Assuming it isn't -

1) you need to make sure the vlan or vlans you want to extend to the 3750 are created in the vlan database on the 3750. You can either do this manually by using VTP transparent or you can make your 2950 switch a VTP server and the 3750 a VTP client.

2) You then need to connect the 2 switches together and configure the ports on both ends as -

i) if you simply want to extend one vlan then assign the ports at both ends into that vlan eg.

2950

int gi0/1

switchport mode access

switchport access vlan 10

3750

int gi0/1

switchport mode access

switchport access vlan 10

ii) if you want multiple vlans across the link then -

2950

int gi0/1

switchport mode trunk

3750

int gi0/1

switchport mode trunk

switchport trunk encapsulation dot1q

Jon

[Damodar Nagar]

Hi,

Firstly thanks for support,

If I will do this step then how to check that our Cisco2950(Live switch) switch cascade with cisco3750(New) switch.

And after cascading we can use same host name for both switch or not..?

Note - we are using vlan for every ports.

Thanks,

Damodar

[Jon Marshall]

Damodar

To check, just connect a device into the relevant vlan on the 3750 and see if it works.

You can use the same hostname for each switch if you really want although if you use DNS and telnet to the swirtch by hostname not IP you won't be able to. Why would you want to do this ?, it would just create confusion. I would recommend using a different hostname per switch.

Or do you mean hostname of the device connecting to the switch ?

Jon