RV320: Need to use as gateway for multiple subnets

[precept]

We just purchased an RV320 as a replacement/upgrade to an RV042. Our Internet connection was upgraded to 200Mbps and the RV042 wouldn't handle that throughput.

Our internal network has 4 subnets, all connected via a layer 3 switch. The RV320 is connected to one of those subnets and is the default gateway for the entire network.

The RV042 had a "multiple subnets" setting that allowed it to perform NAT for the directly connected subnet and the other 3 subnets in our network. We would just add the other networks to the list in the RV042 and everything was fine.

The RV320 doesn't seem to have the same functionality (or am I missing something?). It looks like there is some sort of multiple subnet support, but when we try to add another subnet the interface seems to be asking us to define a single IP address in that subnet (an IP address for the router?) as if all subnets will be directly attached to the router using VLANs (which is not the case in our network).

We can set up the "advanced routing" option to define the other 3 internal subnets and how to route to them, etc. but will the RV320 perform NAT for the other subnets without any adidtional configuration?

Can anyone shed any light on this?

Many thanks!

[Ismael Arroyo]

Precept,

My name is Ismael, iam with Small Business Support Center. I like to start by asking is there a  particular reason that the switch is handling Layer 3/or DHCP? Normally when an RV042 is implemented you would need a Layer 3 switch as the RV042 only supports one DHCP scope.In addition all The RV0XX series does not support 802.1q VLAN.

With RV320 you can setup multiple subnets under advance routing and still allow for it to pass DHCP for all of your 4 subnets and create 801.2q Vlan subinterfaces . Setting RV320 in this manner can create an ease in managing the network.

If you are considering the RV320 to do Layer 3 / DHCP simply create your 4 Vlans or subnets. Add them to the DHCP scope and enable DHCP server for all subnets. Switch would have to be configured to Layer 2 for this to work.  The link below is a knowledge portal that could assist in creating DHCP and Vlans. Hope this helps you.

http://sbkb.cisco.com/

[precept]

iarroyo,

We don't need the RV320 to perform DHCP or any Layer 3 routing. All DHCP and internal routing betwen the subnets is performed by our internal switch (Catalyst 3750).

We just need the RV320 to act as our Internet gateway for all 4 internal subnets:

RV320<-->Subnet1<-->Catalyst3750<-->Other subnets

The RV320 is set as the default gateway for the entire network. Any computer on Subnet1 can access the Internet and the RV320 performs NAT. 

We've set up advanced routing in the RV320 and it can ping all devices on all the other subnets.

How do we tell the RV320 to perform NAT for the other subnets? On the RV042 we just add the other subnets into a "multiple subnets" table and it works. The RV320 doesn't seem to have the same capability. We don't want to connect the other subnets directly to the RV320... they have to route through the 3750.

[Ismael Arroyo]

precept

With RV320 being in place for only natting you would have to make the router aware of all the subnets or vlans. First create the vlans under vlan membership. After thats done you would need to configure static routes under Setup>>advance Routing. Point all static subnets or vlans to the  Gateway of the Catalyst. Lastly, not sure if you had a P2P link involving a /30. This is mainly a static set for GW of the router with subnet of 255.255.255.252. Hope this helps you.

[precept]

Thanks ismael.

Would the link between the Catalyst and the RV320 need to be a trunk port?

[Ismael Arroyo]

Precept,

If you configure that port to be P2P link configure that interface to be a routed port.