SRP527 Nat & 3560

[peter.cashen]

Hi All,

Trying to configure an SRP527 to work in conjunction with a 3560G switch....

My local subnet on the 3560 is 172.23.x.x

The subnet on SRP527 is 192.168.x.x

Everything can ping each other, except I just cannot get any internet access from 172.x through 192.x and out....?

Does the SRP527 support this?

[Andrew Hickman]

Hi Peter,

This is a limitation of the SRP527 - it will only NAT traffic from directly connected subnets.

Regards,

Andy

[peter.cashen]

Hi Andy,

So unless my servers on the 3560 are in the 192.x subnet they will not pass through the SRP527?

Peter

[Andrew Hickman]

You can add new VLANs to the SRP and change the IP address range of each.  But yes, traffic will only be translated if it originates from an IP subnet directly connected (from a routing table perspective) to the SRP.

[peter.cashen]

Great...

Ok, so If i need to route my 172 traffic through to the net, I need to create a VLAN on the SRP with the following details:

Vlan Name: Test

VLAN ID: 10

Address Type: ?? What do I choose here??

Available interface: Do I choose the interface what my 3560 is plugged into?

[Andrew Hickman]

What you really need to do is move the layer 3 interface from the 3560 to the SRP to achieve this - or at least make the SRP the default gateway for the server subnet.

For address type, choose static addressing (or DHCP server if you would like the SRP to offer addresses for this subnet).

Add the SRP interface that is connected to the 3560 to the assigned interfaces.  As soon as more that one VLAN is assigned to an SRP port, it will be converted to a .1q VLAN trunk, so you will need to configure the 3560 interface similarly - ensure that you allow the server VLAN ID on that trunk interface.

I assume that VLAN 10 is your server VLAN - the VLAN ID will need to be the same on both the 3560 and SRP in this case.

If you have other IP subnets on the 3560, you will need to make sure that the SRP offers a route back to these somehow (via a different subnet perhaps) for the Server subnet.

HTH

Andy