Re: [44net] Traffic not routing to my gateway

Well, it is not very straightforward so when it is your first script you are probably going to have a hard time... In Linux there is a point-to-multipoint IP tunnel, much as was the case in JNOS when this whole IPIP mesh was designed. You configure only a single IP tunneling interface, usually called tunl0, and you put a set of routes in the route table with the destination subnets, the tunl0 device, and the remote endpoint of the tunnel as the gateway address. Like this: 44.2.2.0/24 via 216.218.207.198 dev tunl0 onlink 44.2.7.0/30 via 73.185.12.233 dev tunl0 onlink 44.2.10.0/29 via 104.49.12.130 dev tunl0 onlink The onlink attribute is required to suppress the "gateway not reachable" warning you would normally get when the gateway is not directly reachable from the system. With this facility, the updating is relatively easy: just make sure the actual routing table agrees with the distributed information, by adding and deleting single routes. Without such point-to-multipoint tunneling, you will have to create a separate tunnel interface for each gateway, and setup routes to the remote subnets pointing to the correct gateway tunnel. Remember there are (way) more subnets than gateways, you need to find the routes with the same remote gateway, and create only a single tunnel device for those combinations, and point the matching subnet routes to that device. To obtain the information about the subnets, you either listen to the RIP broadcasts made by amprgw, or you regularly download the "encap.txt" which has this format: route addprivate 44.2.2/24 encap 216.218.207.198 route addprivate 44.2.7/30 encap 73.185.12.233 route addprivate 44.2.10/29 encap 104.49.12.130 so you need to parse that and get the subnet and gateway fields from it. (this format is the commandline format that JNOS used) There is no separate "list of endpoints" so you have to create that yourself from that list of routes (take the last field and put it in a list, removing duplicates). Now when you have written a script to transform this into commands to create the proper tunnel devices and add the routes, the real fun begins! The next time you get the information, you need to check if there are changes. When there are, there usually will be a change of tunnel endpoint address (for a gateway that is on a dynamic internet address). You will find several entries in the information that suddenly have a different next hop address, but of course they are not grouped together, they are scattered through the lines you received. You will need to locate the correct tunnel device (which you will need to look up using the *previous* table of received information) and change its endpoint. But, there are other possibilities, ocurring less often: a subnet could have been added or removed from a gateway (and maybe moved to another), a new gateway can be added, or a gateway can be removed (with all its subnets). And of course, combinations of the above, e.g. a gateway has its endpoint address changed and at the same time adds or deletes a subnet. That is probably a rare occurrence, but it should not cause disaster (like a crash). Of course you could simplify things by just deleting everything (routes and devices) and rebuilding it from zero whenever there is some change. But that could cause brief interruptions of the routing and/or high load on the CPU. Sure, it can be done. But for someone who is not experienced in programming in general, and has to learn the scripting language for the particular platform as well, it will be tough. I would certainly advise to look at Marius' script for MikroTik, as it of course has the algorithms described above. It would have to be rewritten in a different language and the constructs to add/delete tunnel devices and routes will have to be changed. Rob