Cisco Catalyst 2960 48 ports

[Manor84]

Hello,

I just landed to a new small IT company.
We have the Catalyst 2960 but no Vlans are configured.
We have around 65 hosts and 10 different servers.

What is the idle way, the shortest network downtime, to start segmentation of the network through vlans?

Thank you!

 

[cajuntank]

Problem is, the 2960 series of switches from Cisco are layer 2 only switches, so if you want to create VLANs, that's fine, but you must have a device that can route those VLANs your create. This can be done with a traditional router, but my suggestion is get a Cisco 3750 series switch to use as your core switch. This is a layer 3 switch so you can create your different VLANs on this switch, enable ip routing on the switch, propagate those VLANs down to your 2960 switches via VTP, plug your servers into the core and nodes into the 2960's which become your access switches. The 3750 switch will be your default gateway/router for your network, then you can establish a route from it to your firewall/router to Internet.

I am not a Cisco product guru, but I believe these switches are also capable of being stacked together, so if you need to increase redundancy, you can get two, stack them together, run two uplink cables from each of your 2960's to each of the 3750's in the stack. Most servers come with dual if not quad NICs, so the same can be done there also. This way, if you have a switch go down, your still up as the other switch is running and you have redundant links from your servers and from your 2960's.

Hope that helps.

 

[Manor84]

Hi,
thank you.

We do have router, Cisco 1811W. Would I have to change configuration on the routers if I add those Vlams on the switch.
Also; when I referred to downtime I was wondering if I will have to change IP addresses of the hosts, since now they will be link to vlans ports on the switch.

Thanks.

 

[cajuntank]

If you are going to use the 1811W as your core layer 3 device, which you can certainly do, then yes. You will create sub interfaces on the ethernet port to match up with the VLAN tags you create on your switch. The term is "router on a stick" and you can google search that phrase and get many config examples.

Depends on if you are changing the hosts onto the other subnet you create, then yes, but you would normally handle that via DHCP. Just create a new scope and add the ip helper-address command to the router's subinterface section on the new subnet pointing to the DHCP server on the existing subnet you had.

 

[Manor84]

Thank you.