On Tue, 11 Nov 2003, Peter Nelson wrote: > Ok, I'm pretty new at this and am probably in a bit over my head, but I > was looking for some pointers. I want to classify and then prioritize > traffic based on if it is to an Internet2 host, a host on campus or the > general internet. I got a dump from one of our campus's routers that > classifies everything as either I2 or local, only problem is that it is > ~8000 entries. Now a lot of those entries can probably be combined down > (for example a couple of sequential /24's). My first question is does > anyone have any script that you give it multiple netmasks and it > combines it down to the simplest netmasks? Now my second question is > would using hashtables, maybe even nested ones be practical for this? > This is how I'm thinking of hashing so far: > > Mask hashes children to check > 0xFF000000: 100 most 50-500 > 0xFFFF0000: 3000 most <20, some 50-200 > 0xFFFFFF00: 8000 all < 10 > You can link hashes to do what you want: hash (made from first byte of the ip): 01 -> another_hash_1 10 -> another_hash_2 another_hash_1 entries (hash made from second byte): 01 -> another_hash_on_level_2 10 -> another_hash_on_level_2 and so on. > Obviously hashing based on 0xFF helps, but it still has to go through up > to 500 checks for somes hosts. Once I hash based on 0xFFFF the worst > case gets a lot better, and of course hashing on 0xFFFFFF makes almost > perfect hashes. Only thing is does a hash table lose it's point once > you start indexing everything? I was thinking maybe hashing based on > the 0xFF and then from there making hashes based on 0x00FF (and then > maybe an other layer of 0x0000FF). I admit I really don't know all that > much about the hashing algorighm and it's complexity so I don't know how > to approach this. > > Thanks for any information, > Peter Nelson > _______________________________________________ > LARTC mailing list / LARTC@xxxxxxxxxxxxxxx > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ > --- Catalin(ux) BOIE catab@xxxxxxxxxxxxxxx _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
