On Linux, one can set up a single IPIP interface without defined destination endpoint and direct traffic to multiple endpoints by using special crafted routes.
e.g.
ip tunnel add tunl0 mode ipip local 2.3.1.2
ip route add 1.2.3.0/24 via 5.6.7.8 dev tunl0 onlink
ip route add 2.3.4.0/24 via 6.7.8.9 dev tunl0 onlink
This will encap traffic to 1.2.3.0/24 via destination 5.6.7.8 and traffic to 2.3.4.0/24 to destination 6.7.8.9,
while having a single ipip tunnel interface. Incoming traffic is of course received from both partners in that interface.
Is there a point to multipoint IPIP encapsulation setup possible on ROS?
I need to use a IPIP tunnel mesh setup, with some three hundred of endpoints, and setting up an interface for each partner in nor practical, nor possible. (generating them by script somehow stops at 19 interfaces).
An openwrt metarouter can do this, but that requires a slow mipsbe router (so no PPC or Tilera), and is sometimes unstable.
You can have the same ip on the server side of sstp tunnels for example. Or you can use eoip tunnels even without ip address assigned to them and enslave them into one common bridge.
I like to integrate the router into an existing IPIP full mesh system, which is serviced at the moment by a linux machine.
This system is IPIP point to multipoint. It is not an issue of IPs, it is an issue of having to set up more than 300+ tunnels instead of 1.
I think the IPIP tunnel driver probably supports the NBMA mode (since there’s a linux kernel at work), just the CLI doesn’t allow to set up a tunnel without a predefined remote address.
And the route IP%interface syntax is there, but not the “onlink” option (to assume it is always reachable).
I agree it would be nice if RouterOS supported multipoint IPIP, in the form of an IPIP interface without remote address
combined with a list of routes that define the remote address for each remote subnet.
It is a standard facility in Linux. It appears that only the support is missing from the MikroTik management layer.
It should be comparatively easy to add this to RouterOS and would make it more useful as a router in the network that
docmarius describes.