Layer 3 Switch Configuration

Hey Guys,

I ran out of IP addresses, it seems our WLAN and Phones are using up a lot of IPs. We have some dummy Cisco SG200 switches in the environment (about 3). Now i got a layer 3 (Cisco 3750x) switch, and I was wondering if this would be sufficient.

L3 SWITCH ( --> Firewall
Route outside 0 0

-Im just going to use the default VLAN 1 and connect the SG200 (dont want to try and trunk these - i hate those
-The wireless APs i will directly plug into the L3 switch and assign them to VLAN2 (10.1.2.x)
- Use ip helper to my DHCP server on the 10.1.1.x network

Would this all work?
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Elango SathyadevSenior Systems EngineerCommented:
This will all work if you have the environment configured properly. Cisco L3 is the key along with DHCP server.
Cobra25Author Commented:
What does configured properly mean. Is this OK or not?
If I recall properly, you'd still have to do VLAN configurations in the SG200s. They won't just pass along all of the VLANs.
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Cobra25Author Commented:
Why? I kept everything the default vlan 1
I reread after I typed that. Actually, it sounds like what you want to do should work.
Generally, your plan should work, but I  don't think it is enough...
Phones should be in separate VLAN and have own IP address range (just like WAPs). SG200 are manageable switches and although you hate those you should start use it properly. Network is growing and it is the best time to start to plan for the future, most likely, soon you will have more problems than just IP address is too small.
Cobra25Author Commented:
Yes, I know. Will do that later.
If firewall is connected WAN device route on 3750 is actually:
ip route
Since you are planning to use 3750 to terminate 10.1.2.x you will need also route on firewall
Route outside 0 0 <ISP_ip_address>
route inside

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Cobra25Author Commented:
Oh yeah, almost forgot about that. It's a Sonicwall firewall though
Just a thought... Why not just let the Sonicwall handle the work of DHCP and VLANs?
Cobra25Author Commented:
Sonicwall is going to be decommissioned in a month.
Makes sense. However, I'd assume the replacement firewall would be capable of the same duties.
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