IP Filtering / CIDR Block Size / SprintLink

Alex P. Rudnev alex at Relcom.EU.net
Tue Jan 28 10:43:25 UTC 1997

On Mon, 27 Jan 1997, James D. Butt wrote:
> > Who, in addition to SprintLink, is currently implementing IP 
> > filtering based on CIDR block size (/19)?  And where can I go 
> > to learn more about this issue?
> I beleive AGIS has filters now. You can get the specifics off www.agis.net
> and click on Network Engineering and read the Nanog presentation info.
> The best place to go is the nanog archives...for more information about
> other providers...
Hmm, there is amazing - I understood 2 cases only -
It's not big difference for us if there is 1 or 10 big ISP who make 

But - all you know this filtering have 2 sides. First, it decreases 
routing noice in the network. But, 2'th, it prevent address space saving. 

It seems (reading your mail) /19 filtering is too raugph for the 
INTERNET. It seems it's nessesary to have some filtering to prevent extra 
grouth of the routing tables. Ok, why nobody discuss /20 or /21 filtering 

I must repeat - it's not important for the small ISP and small 
enterprises how many ISP over the world produce filtering - it's 
important if the filtering exist somewhere or not. 

Aleksei Roudnev, 
Network Operations Center, Relcom, Moscow
(+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 239-10-10, N 13729 (pager)
(+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)

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