Friends: People keep sending me e-mail asking for my ideas on alternatives to renumbering and CIDR. Here is a very rough strawman idea just posted to the CIDRD-WG. There are similar variations on this ASN routing paradigm that also could be considered: VR, Tim PS: I'm off to the Azores in Portugal Monday for three weeks, so hopefully I can find net access to see how much of a flame-fest my mbox is enjoying..... ***************************************************************** STRAWMAN Autonomous System Aggregation Protocol (ASAP) --------------------------------------------- Too simple, by a simple minded person.... :-) 1) Modify IP code in routers to route with ASN numbers between AS; 2) Modify core routers to add ASN numbers to IP packets by; i.) Temporarily using TOS or similar field(s) in IP header; ii.) Add proper hooks in next version of IP; iii.) Some better idea. 3) Develop details of new routing algorithm to route, filter, load balance, multi-home using ASN tags; 4) Modify core routers to add ASN tags to IP packets that do not have ASN tags assigned by originating host (for backwards compatability with version of TCP/IP that cannot add their ASN numbers to IP headers (or a better idea); 5) Modify core routers to transfer routing from the ASAP protocol to the appropriate IGP if-and-only-if ASN of destination matches the current ASN; 6) Create simple UDP based algorithm (similar to DNS) that manages a distibuted database that maps IP addresses to ASN numbers. For example: When sending a packet, the kernal checks its cache for a map between the IP address and ASN number. If it existing is the cache (get a hit) it adds the ASN destination number to the IP header..... if not the router or host sends a UDP packet to a distributed database that maintains the mappings.. (these could be local, remote, but distributed and caching each other ... in a similar, but more efficient manner than DNS (after all how often do IP networks change their home ASN) (instead of ARP.... its ASNRP...... ;-) 7) Create another database of SUPERNETTED ASN numbers for IP service providers that aggregate current ASN numbers into some meaningful structure and provide distribued SUPER-ASN to SUPER-ASN routing. 8) More ideas to develop and refine.... Advantages: 1) IP address space allocation is simplifed and renumbering not necessary; 2) ASN routing reduces the size of the routing tables ; 3) SUPER-ASN routing further reduces the size of ASAP routing tables; 4) Routers can add ASN tags to IP packets until users migrate to new IP kernels; 5) More.... but I'm packing for a trip... Disadvantages: 1) Must create new ASAP protocol and SUPER-ASAP protocol; 2) Must create distributed ASN-NETWORK database; 3) IP code must be modified and upgraded; 4) Non-cached initial packets will route slower mapping destination ASN to destination IP address. 5) Also more disadvantages..... Just a start.... needs work.... but living in a plane is a real drain.. :-) Tim +--------------------------------------------------------------------------+ | Tim Bass | #include<campfire.h> | | Principal Network Systems Engineer | for(beer=100;beer>1;beer++){ | | The Silk Road Group, Ltd. | take_one_down(); | | | pass_it_around(); | | http://www.silkroad.com/ | } | | | back_to_work(); /*never reached */ | +--------------------------------------------------------------------------+