inter-vlan communication is not possible.

Unanswered Question
Jun 30th, 2009
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Hi Sir,

i have 2 layer 3 switch 3750 series. i need to configure this swich with 3 vlans( say as vlan 100-, vlan200- and vlan 300-

it is neccessary to communicate each vlan to other vlans.

Kindly give configuration solution so that i can make my network perfect.


Siddhartha Singh

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xcz504d1114 Tue, 06/30/2009 - 07:00
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In order to route between 2 VLAN's you need a layer 3 device. In this case you can use your 3750's by enabling routing. To enable routing type "ip routing" under global configuration.

You do not need any routing protocols (such as rip or EIGRP) if you are routing to only directly connected networks (IE: You put all three of those IP addresses on the same switch that you enable IP Routing on).

Don't forget to point your clients to the IP addresses of each VLAN's as a default gateway.

If you are trying to split those IP addresses between each switch, (IEL on Switch 1 and on Switch 2, you will need to enable a routing protocol such as RIP and advertise the networks.)

In order to do this the commands are as follows:

On Switch 1:

ip routing

router rip

version 2


On Switch 2:

ip routing

router rip

version 2


You can then view the routing information by issuing "show ip route"

Keep in mind that in order to use any other routing protocols on a 3750, you must be running an advanced IP services IOS.




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