Jerry,
As for how the attribute is actually used, I found 2726 route objects with the attribute. Of these, there are only 111 unique origin AS. As for the AS actually listed as the target of the advisory, there are only 13 unique AS! The actual frequencies are:
This suprises me since to my knowledge we no longer supported this attribute. So I grep'd our production DB cache for 'advisory' and it did not show up.
So where are you finding all these occurences?
Well, nobody bothered to tell the world it was deprecated. As anyone with experience with large databases know, any possible gorp quickly starts to get added. :) Some recent examples: route: 195.144.128.0/19 descr: INS Core/Customer Network descr: ALLOCATED PA Space do not break up origin: AS5378 advisory: AS690 1:5378 2:701 mnt-by: AS5378-MNT changed: robertwo@insnet.net 20000731 source: RIPE route: 62.177.0.0/19 descr: SIR origin: AS3269 advisory: AS690 1:701 2:1800 notify: network@cgi.interbusiness.it mnt-by: INTERB-MNT changed: cgiadmin@cgi.interbusiness.it 20000727 source: RIPE route: 193.195.0.0/16 descr: DEMON-INT-NET origin: AS2529 advisory: AS690 1:1239(147) 2:1239(218) remarks: Send Abuse reports to abuse@demon.net mnt-by: AS2529-MNT changed: sam.bradford@demon.net 20000714 source: RIPE route: 193.180.216.0/24 descr: SWIPNET origin: AS1257 advisory: AS690 1:1800 2:1133 3:1240 notify: staff@swip.net mnt-by: AS1257-MNT changed: ip@swip.net 20000616 source: RIPE % had to search back a ways for an advisory to someone other than AS690 route: 213.132.128.0/19 descr: UPC Belgium (Radio Public) origin: AS8733 advisory: AS702 702:2 702:120 3300:2001 3300:3001 3561:90 advisory: AS1755 1755:2204 advisory: AS6830 3300:2005 3300:3002 3561:110 mnt-by: AS8733-MNT changed: steven@tvd.be 20000124 source: RIPE Maybe there's a script out there cutting and pasting these objects? I don't know. There sure are plenty, though. People *seem* to be doing it for a reason. Maybe somebody invented a real use for this? -- Shane Kerr <shane@ripe.net> Database Software Engineer RIPE NCC +31 20 535 4427