Any people still with old filters?
In a recent discussion with a company that owns a /16 and has it broken down further, the statement was made that there are ISPs that filter routes at /16 in what was traditional class B space. The example cited was Verio. Verio web pages state they don't do this any more (the filter is /21). Is there anyone that still filters routes longer than /8 and /16 in the traditional Class A and B space?
No. If they did, 80% of the internet would not be visible to them today., --Phil -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Roy Sent: Saturday, July 27, 2002 4:54 PM To: nanog@merit.edu Subject: Any people still with old filters? In a recent discussion with a company that owns a /16 and has it broken down further, the statement was made that there are ISPs that filter routes at /16 in what was traditional class B space. The example cited was Verio. Verio web pages state they don't do this any more (the filter is /21). Is there anyone that still filters routes longer than /8 and /16 in the traditional Class A and B space?
No. If they did, 80% of the internet would not be visible to them today.,
sure. and pigs fly. I don't think that anyone have ever filtered on old class-based sizes. What I know is that the most restrictive filters have been on RIR allocations boundaries, and for old "non-returned" A:s and B:s there have bene filters on /8 and /16. Swamp space have never been filtered. ...and the clue-less on the Internet is (still) less than 80%. It's more like 20%. See http://mcvax.org/~jhma/routing for one example of how much we could gain if we actually aggregated... - kurtis -
...and the clue-less on the Internet is (still) less than 80%. It's more like 20%. See http://mcvax.org/~jhma/routing for one example of how much we could gain if we actually aggregated...
This was hinted at in the peering debate, but wouldn't it help the cause of aggregation if networks stopped requiring a large number of prefixes in order to establish peering? -Ralph
...and the clue-less on the Internet is (still) less than 80%. It's more like 20%. See http://mcvax.org/~jhma/routing for one example of how much we could gain if we actually aggregated...
This was hinted at in the peering debate, but wouldn't it help the cause of aggregation if networks stopped requiring a large number of prefixes in order to establish peering?
Interesting point. But peering is a commercial relationship. Basing it on number of prefixes is IMO a wierd view, but yes that is done. It CAN be a meassurement, but hopefully people using it as an argument is clever enough to actually look at the routes - not just the numbers of them. I seriously doubt that this is the real reason for the routes though. Best regards, - kurtis -
In the referenced message, Roy said:
In a recent discussion with a company that owns a /16 and has it broken down further, the statement was made that there are ISPs that filter routes at /16 in what was traditional class B space. The example cited was Verio. Verio web pages state they don't do this any more (the filter is /21).
Is there anyone that still filters routes longer than /8 and /16 in the traditional Class A and B space?
Assume this is the case, announce your largest aggregates, and reduce the likelihood of ever having a problem in the first place. This does not prevent you from advertising additional more-specifics to entities who have agreed to accept them, nor does it prevent others from filtering them. In the end, you still have connectivity, and only those who wish to see the more-specifics, will.
participants (5)
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Kurt Erik Lindqvist -
Phil Rosenthal -
Ralph Doncaster -
Roy -
Stephen Griffin