Vlans on R180W to separate networks

[JustinPaterson]

Good Morning,

I have a network set up between two buildings.  Each building has its own internet connection and DHCP server, building A using an RV180W router and building B using a linksys product.  A WDS bridge has been set up between the two buildings using two wireless access points.

The goal here is to allow clients in either building to be assigned an IP from their respective DHCP server (and thereby use that building's internet connection), yet still access network resources (eg file storage, printer, etc.) in the other building should the need arise.

I have tried to set this up by having the RV180 assign IP's in the range 192.168.0.xxx to its clients in building A, and the linksys to assign IP's in the range 192.168.1.xxx in building B.  I have enabled Vlan 1 and Vlan 2 on the RV180 - vlan 1 runs a DHCP server for building A.  Vlan 2 runs no DHCP server and is directly connected to the WDS bridge to building B.  Inter Vlan routing is enabled on both Vlan 1 and Vlan 2.

On the WDS bridge modules, ive assigned both static IP's in the 192.168.1.xxx range (vlan 2 range).  I've specified their dns and default gateway as 192.168.1.2 which is the static address for the RV180 in vlan 2.

From a PC in vlan 1, I can ping and access the webgui for the WDS bridge modules which are in Vlan 2.  However, i cannot ping any other computer in Vlan 2 which is set to accept a dynamic IP from the DHCP server operating in Building B.  I assume this is because the WDS modules point to the RV180 as their default gateway and dns server, while the clients that have accepted a dynamic IP from the building B DHCP point to that device as their default gateway and DNS.

Can anyone assist me in this regard, or is there a better way to be doing it?  Is it even possible?  I am considering trying changing the DNS and default gateway on the building B side of the WDS bridge to the building B values to see if that helps, but am concerned i would lose all connectivity to the webgui from building A if i do that.  What about a DHCP relay?  Any help is much appreciated.

Justin

[Clayton Sill]

Hello Justin,

     Sounds like you need to create some static routes. Could create a route on the RV180 stating destination ip go to 192.168.1.0 and the next hope/default gateway be 192.168.1.1 (I am assuming that is the default gateway of the Linksys router). So on the linksys you would create a route stating destination ip go to 192.168.0.0 and next hope/default gateway be 192.168.1.2.

I'm trying to write this out and think it out in my head but that is what I have come up with so fare. I feel like I may be missing something still but let me know if that makes a difference or not for you so fare.

Edit: The other question I meant to ask is can you ping the linksys router?

Thanks,

Clayton Sill

[JustinPaterson]

Thank you for your reply Clayton.  I cannot ping the linksys router from Vlan 1, i can only ping as far as the "far" end of the WDS bridge (which is in Vlan 2) from within Vlan 1.  I am suspicious this is because the gateway and dns on both these appliances point to the RV180.

I've made a crude diagram of the present setup to help clarify.  I am definitely not a network pro so i sincerely appreciate the help.

Justin

[Clayton Sill]

Hello Justin,

     Yeah I'm trying to think if this is possible or not. It seems like it would but the default gateways are going to be hard part and you are right though. The reason you can ping the bridges is because they know were to send the traffic back.. the linksys just doesn't know how to reach that network and you have to create static routes to tell it were to go. When you try to ping the linksys router, the reason you don't get a response back is because it doesn't know how to reach the 192.168.0.xx network unless you create a static route.

Thank you for the topology though, try the static routes first if you haven't already and we will go from there.. I would hope you can create static routes in the linksys.

Edit: I'll also see if I can think up of a different toplogly but it looks right so fare. If I have time I'll see if I can get someone else opinion on this.

Thanks

Clayton Sill

[JustinPaterson]

Clayton, i will try the static route option.  I am going to attempt to set a static route between the two routers.

I've gotten as far as adding one (i think) into the RV180 by means of this article

http://sbkb.cisco.com/CiscoSB/GetArticle.aspx?docid=11cd4f96c49840b0810ec59ebc3e8c8c_Static_Routing_Configuration_on_RV180_and_RV180W_.xml&pid=2&converted=0

Based on the network topology, I've assumed the following:

Destination IP 192.168.1.1 (the linksys router)

Subnet 255.255.255.0

Interface LAN

Gateway IP is 192.168.0.1 (the RV180 router)  This is the entry i'm not sure of.  Am i right in my guess?

I assume then i would add basically the "reverse" route into the linksys router and then test ping between.  Is this more or less correct?

Is there another, perhaps less impossible way to filter DHCP broadcasts on a specific port ont the RV180?  I guess my thought would be then we could assign IP address on either side on different parts of the same range and then it would function more like one big network.

Justin

Edit: interesting new development.  I used the ping utility on the RV180W and was able to ping the linksys router at 192.168.1.1.  Is this then a problem with inter-vlan routing?

[Clayton Sill · Accepted solution]

Hello Justin,

     Yeah you may have to play around with the static routes a little to find the right one.. I am trying to think of which would be the best route.

No the inter-vlan routing should be working. The reason it isn't is because the RV180 is doing the routing.. if you default gateways are pointing at the Linksys then it doesn't know how to do intervlan routing.. so that is why the static route comes into play.. you are telling the traffic how to get to the RV180 so it can do the intervlan routing.. the traffic is just not going to the RV180w at this point.

The reason the router is able to ping the linksys because they are on the same subnet.

I would try creating a static route like this..

RV180:    Destination IP 192.168.1.0

               Subnetmask: 255.255.255.0

               Default gateway/nexthope: 192.168.1.1

Linksys: Destination IP 192.168.0.0

               Subnet mask: 255.255.255.0

             Default gateway/nexthope: 192.168.1.2

The linksys rule is the important one. It is telling the linksys, if you are trying to reach network 192.168.0.0 you need to go to 192.168.1.2 first instead of going to 192.168.1.1 pretty much. Once the traffic goes to 192.168.1.2 the RV180 will now how to get it to 192.168.0.0 network because of the intervlan routing.

You may not need the static route in the RV180.. try the static route in the Linksys but it wouldn't hurt to add the static route in the RV180w as well.

I think you should be good to go at this point. Let me know how it works out!

Thanks,

Clayton SIll

[JustinPaterson]

Clayton: some measure of success here now.  I'm "dry testing" this setup, so i've set up another linksys router and connected it directly to the RV180 (removing the potentially complicating factor of the WDS link).

I've added the routing rules you've indicated to both routers, with the proviso that the RV180 will not let me declare the gateway as 192.168.1.1.  It requires it to be within the range 192.168.0.xxx so i set it to 192.168.0.1 (which is the address for the RV180.

The rule exactly as you suggested above went in fine to the linksys so i am not sure what the roadblock is there...

With a PC connected to the linksys router, i now take DHCP addresses in the linksys's range of assignment, yet can still ping across to a PC connected to the RV180.  However, PC's on the RV180 cannot ping anything after the linksys router.  From the RV180 side, I can ping the linksys router, and pull up its webgui on 192.168.1.1, but i cant ping a connected PC with the address 192.168.1.42

Any ideas why this might be?

EDIT: This one i resolved on my own, it turns out there was a firewall running on the PC i could not ping.  Upon disabling that, the routing between the two network segments (at least as far as ping goes) appears to be fully operational in both directions.  Clayton, big thanks to you sir!

[Clayton Sill]

Hello Justin,

     Ah! I forgot about the firewalls in the PC's. Yeah they will block pings by default if they see the traffic coming from a different network. So you'll have to create a firewall rule in windows allow ICMP packets to come through while keeping your firewall enabled. Yeah I think just the rule in the linksys will work fine though since the RV180 already knows how to reach the linksys router.

Glad I was able to help you out though Justin! I hope you have a great day.

Thanks,

Clayton Sill