North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: commonly accepted prefix length filters?
Some people use filters such as the example provided ip prefix-list bad-nets-in description input prefix-list for BGP sessions ip prefix-list bad-nets-in seq 1 deny 0.0.0.0/1 ge 21 ip prefix-list bad-nets-in seq 2 deny 0.0.0.0/8 le 32 ip prefix-list bad-nets-in seq 3 deny 10.0.0.0/8 le 32 ip prefix-list bad-nets-in seq 4 deny 127.0.0.0/8 le 32 ip prefix-list bad-nets-in seq 5 deny 128.0.0.0/2 ge 21 ip prefix-list bad-nets-in seq 6 deny 128.0.0.0/16 le 32 ip prefix-list bad-nets-in seq 7 deny 169.254.0.0/16 le 32 ip prefix-list bad-nets-in seq 8 deny 172.16.0.0/12 le 32 ip prefix-list bad-nets-in seq 9 deny 191.255.0.0/16 le 32 ip prefix-list bad-nets-in seq 10 deny 192.0.0.0/3 ge 25 ip prefix-list bad-nets-in seq 11 deny 192.0.0.0/24 le 32 ip prefix-list bad-nets-in seq 12 deny 192.0.2.0/24 le 32 ip prefix-list bad-nets-in seq 13 deny 192.168.0.0/16 le 32 ip prefix-list bad-nets-in seq 14 deny 198.32.175.0/24 le 32 ip prefix-list bad-nets-in seq 15 deny 198.32.176.0/24 le 32 ip prefix-list bad-nets-in seq 16 deny 198.32.177.0/24 le 32 ip prefix-list bad-nets-in seq 17 deny 223.255.255.0/24 le 32 ip prefix-list bad-nets-in seq 18 permit 0.0.0.0/0 ge 1 On Fri, Apr 27, 2001 at 04:06:31PM +0100, Stephen J. Wilcox wrote: > > I'm seeing 103000 routes.. > > I imagine the limit on what you discard has to be that of the smallest > block of addresses that the registries will allocate, as if you filter > anything smaller you will start to lose genuine networks. Not sure what > that limit is, /24 ? > > Steve > > On Fri, 27 Apr 2001, Jim Mercer wrote: > > > > > > > our bgp tables are starting (?) to get out of hand. > > > > we are thinking maybe we should start nuking some routes in order to reduce > > the size of the tables. > > > > is there a list of commonly accepted aggregating prefix filters? > > > > > > > > -- > Stephen J. Wilcox > IP Services Manager, Opal Telecom > http://www.opaltelecom.co.uk/ > Tel: 0161 222 2000 > Fax: 0161 222 2008 > >
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