Solved: Cannot access Internet after configure inter-vlan routing using a Catalyst 3550 switch

andrewla1212 · ‎02-24-2010

My network used to be one vlan (vlan1). All devices on the network to point to my PIX as the default gateway to the Internet. Since, I vlan-ed the network into multiple vlans using the ip routing feature on the 3550, I cannot access the Internet.

I basically follow the sample configuration found on the Cisco Document ID 41260 (Configuring InterVLAN Routing with Catalyst 3750/3560/3550 Series Switches) to setup the attached Cat 3550 configuration. The Pix configuration is my current one flat layer network configuration.

Please advice as to what I missed or did wrong that I cannot access the Internet with this setup. Thanks

Giuseppe Larosa · ‎02-24-2010

Hello Andrew,

>> The Pix configuration is my current one flat layer network configuration.

PIX configuration has to be updated to:

be able to route to the C3550 the new private IP subnets

be able to NAT for the new private IP subnets

looking at your current configuration we see:

nat (inside) 1 192.168.0.0 255.255.255.0 0 0

you need also:

nat (inside) 1 192.168.2.0 255.255.255.0 0 0

route inside 192.168.2.0 255.255.255.0 192.168.101.253

this for each new subnet like 192.168.20/24

Hope to help

Giuseppe

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Giuseppe Larosa · ‎02-24-2010