North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: all the mails on Filtering
Hi, But it appears that there are many cases where customers prefer to take a prefix from the ISP rather than an RIR even if it is a /19 or a /20 - for example from the /11 of a big ISP, there are 50 /19s and /20s which are multihoming assignments. I was told that this saves the cost of RIR membership for the customer. Moreover, how do we know the RIR makes multihoming assignments from a separate /8 - atleast in the case of RIPE it does not I think (in the case of APNIC it does). If we are of sure of this - i.e. that a multihoming assignment from an RIR comes from a separate section of the address space - we can't filter. Harsha. On Wed, 13 Nov 2002, Jared Mauch wrote: > If you're multihomed you can generally obtain provider indepdent > space from your RIR. > > Most people who do this filtering do it on the RIR boundaries > for their minimum allocation. > > If you are annoucing your provider assigned space > as a /24, they tend to announce the (/14 - /rir-minimum) > so your packets will follow the aggregate. If they > are not announcing their aggregate then you will have > problems. Most people in that case would blame > the provider for not announcing their space. > > - Jared > > On Wed, Nov 13, 2002 at 10:25:53AM -0800, Harsha Narayan wrote: > > > > Hi, > > > > So what happens to multihoming assignments made by the ISP? That means > > the multihoming assignment can't be used as a backup. If the customer's > > connection to the ISP which made the multihoming assignment gets lost, > > then it can't use its multihoming assignments (say a /24) to get traffic > > from some other ISP?! > > > > Thanks to all, > > Harsha. > > > > On Wed, 13 Nov 2002, Buddy Bagga wrote: > > > > > Greets, > > > > > > Look at <http://www.nanog.org/filter.html>. If I remember correctly, Verio > > > used to filter prefixes longer than /19s in classful A range. Apparently > > > this isn't the case anymore. But it would be naive to think that ISP only > > > filter prefixes longer than /24. > > > > > > Cheers, > > > > > > On Wed, 13 Nov 2002, Harsha Narayan wrote: > > > > > > > Are there some ISPs who filter prefixes longer than /19 or a /20?. I > > > > thought they filtered only prefixes which are longer than /24? > > > > > > ~ > > > Buddy Bagga > > > Genuity | BBN > > > > > > > -- > Jared Mauch | pgp key available via finger from [email protected] > clue++; | http://puck.nether.net/~jared/ My statements are only mine. >
|