Inter-VLAN Routing Across Different Addresses

[cgarland3]

So I'm trying to set up this network that has three separate networks each with a different address: Network A is 11.0.0.0 network B is 193.169.30.0 network C is 173.18.0.0. Each network is configured with VLANs: A has VLANs 20, 30, 40. B has 25,50,75. C has 5, 10, 15. In this design, I have one router emulating the "internet": all networks have separate connections to the router. My question is, is there a way to set it up so a host in network a from VLAN 20 can ping a host in network b in VLAN 50? All switches are configured with trunks and access ports accordingly, and I have ROAS set up on all routers as well (besides the middle router) Ill post a picture of the design below. Thanks for any help.

[kubn2]

Hello,

Yes, It's possible as long as routers in your network A and B (and also router emulating internet) know about addresses that are available in these networks. You can set this up using static route so for routers in network A and B simplest way will be adding 0.0.0.0 0.0.0.0 network towards router which emulating internet.
On router which emulates internet add route to 11.0.0.0 255.0.0.0 (or other mask) and point to correct ip address/interface and do the same for network 193.169.30/24.

P.S Also note that it's no longer inter-vlan routing because network A is unaware of Layer 2 design of network B and vice versa. For them there is only a different source ip address but they doesn't know that it's different vlan.

[Martin L]

As kubn2 mentioned; this is possible but it is no longer inter-vlan routing or we don't call this inter-vlan routing but inter-site routing (not officially). Vlan tags are lost once they are processed by Router (even outside interface of ROAS who is doing inter-vlan routing). Behind ROAS router traffic is not tagged and is just routed.
Inter-vlan routing should stay inside your company, inside site or in building. Vlan X in Green area is not same as Vlan X in Yellow.
You could ask ISP to provide L2 VPN to connect 2 sties VLans together (or remote offices to HQ). However, usually those Remote-to-HQ are L3 VPNs.

[Vishnu Vardhan S]

It should be a normal routing with a protocol in place as, try configuring static route.