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How to make vlan communicates each other

I have a stack of 3750 switches, two members.

I just setup two vlans - Vlan 2 and Vlan 3, but PCs on different vlan can't ping each other.

Could you please advise what to do? thanks
1 Solution
The purpose of a VLAN is to keep separations within the same involvement.  However, it is possible to get what you want to work via helper IP's in VLAN 2 and VLAN 3 say x.x.x.2 and x.x.x.3

Also, you can add in static routes in the route table of the PC's so that they are aware the other VLAN's / IP ranges exist.

I would first go with the helper IP addresses as shown below.

sw1(config)#VLAN 2
sw1(config-if)#ip helper-address x.x.x2
sw1(config)#VLAN 3
sw1(config-if)#ip helper-address x.x.x.3

You may have to adjust the helper address based on your network's gateway. The pc's not in VLAN's 2 or 3 should be be able to ping these helper addresses if configured correctly. The backup would be the static route on the PC's host table.
We have that situation often and we use the "router on a stick" approach even though the 3750's do have Layer 3 functionality built-in.  Just by setting up normal routing, the packet from VLAN2 PC will go from the 3750 to the upstream router, the router will naturally move it to the other vlan (normal router function)  and then back down the same connection to the same 3750 to VLAN3 PC.
Don JohnstonInstructorCommented:
Do you have SVIs (VLAN interfaces) for the two interfaces?

Have you configured the PCs to use the VLAN interface IP address as the default gateway?
tonitoni99Author Commented:
thanks, resolved by enabling ip route.
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