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L2 and L3 at the same time

Anna_Katona
Level 1
Level 1

Hello!

 

Can I use Cisco 3750 like a switch (L2) and a router (L3) at the same time?

 

I can't buy another device that could be a router...

 

Thanks for your answer!

5 Replies 5

Leo Laohoo
Hall of Fame
Hall of Fame

Exactly what are you trying to accomplish?

In my network there are some vlans. I have only a switch 3750 and I don't want buy a router. Can I set up switching and routing on my Cisco as if I have a switch and a router separately?

For example gi 1/0/1 - is the interface to Internet, fa 1/0/1 - 1/0/48 - is for connecting of PC and Phones.

I have only a switch 3750 and I don't want buy a router. Can I set up switching and routing on my Cisco as if I have a switch and a router separately?

You need to verify what you are trying to do.  Layer 3 switches do NOT support NAT.  That's one of the features that separates routers from switches.  

 

Depends on your switch and depends on the license.  Some Cat 3K licenses (IP Base) can be upgraded to do routing.  In some cases, depending on the IOS you've loaded, IP Base will support some simple routing protocols such as RIP.

 

How To Configure InterVLAN Routing on Layer 3 Switches

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Posting

As Leo has already described, L3 switches, like the 3750 series, can "route".  (NB: it's this capability that distinguishes L2 vs. L3 switches.)

As Leo also has described, L3 switches often don't have as many features as "routers" and the later 3750 series, the -E and -X models, features are controlled by the installed license.  The original series of 3750 features are controlled by the loaded/active IOS image (which requires different "paper" licenses).

Lastly, as Leo has also noted, the lower licensed 3750s might support a basic routing protocol, like RIP, but same also usually support static and local interface routing.  I.e. you may not need a routing protocol at all.

qasim khan
Level 1
Level 1

yes you can!

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