Hello, forgive me if this question doesn't make a lot of sense. I have quite a bit of experience with VPN's but not so much with GRE tunnels. I'm trying to get 1 device on my network a different public IP to emulate a certain scenario. VPN protocols are not supported in this network but IPv6 on GRE Tunnel is. I have details for this IPv6 GRE Tunnel but need a guide for how to set this up in OpenWRT and only apply it to 1 device on the network. Where could I look for information/guide for someone who has no experience with GRE tunnels to achieve this?
This is sorta helpful, but its showing a setup with 3 different routers. Any further tips or pointers to this setup on a single router?
For a tunnel you need at least 2 endpoints, so you can check the configuration of R1 and R2 from the wiki.
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The router in the center is only forwarding the outer tunnel packets. It could actually be a chain of any number of routers, or no router at all (GRE between two machines on the same LAN). Raw GRE is seldom used on the public Internet since the protocol provides no authentication or encryption. It is useful inside private networks or VPN tunnels.
If the rest of the network already exists, the router you are setting up is R1. The setup is in two parts-- creating the outer tunnel with proto gre, and addressing and routing the inner tunnel with an alias interface of proto static.
If the outer transport is IPv6 you need kmod-gre6, if it is v4 kmod-gre. Either v6 or v4 can travel inside a tunnel regardless of the address type outside.
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