Dec 1997:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems Relationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.19971114.gz.
ASrelation.19971117.gz.
ASrelation.19971119.gz.
ASrelation.19971121.gz.
ASrelation.19971124.gz.

May 1998:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.19980511.gz.
ASrelation.19980513.gz.
ASrelation.19980515.gz.
ASrelation.19980518.gz.
ASrelation.19980520.gz.

Nov 1998:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.19981116.gz.
ASrelation.19981118.gz.
ASrelation.19981120.gz.
ASrelation.19981123.gz.
ASrelation.19981125.gz.

May 1999:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.19990510.gz.
ASrelation.19990512.gz.
ASrelation.19990514.gz.
ASrelation.19990517.gz.
ASrelation.19990519.gz.

Nov 1999:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.19991110.gz.
ASrelation.19991112.gz.
ASrelation.19991115.gz.
ASrelation.19991116.gz.
ASrelation.19991118.gz.

May 2000:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.20000508.gz.
ASrelation.20000510.gz.
ASrelation.20000512.gz.
ASrelation.20000515.gz.
ASrelation.20000517.gz.

Nov 2000:
Undirected (without AS relations) data from NLANR http://moat.nlanr.net/Routing/rawdata/.
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.20001110.gz.
ASrelation.20001113.gz.
ASrelation.20001115.gz.
ASrelation.20001117.gz.
ASrelation.20001120.gz.

May 2001:
Undirected (without AS relations) data from ANTC http://antc.uoregon.edu/route-views/ (though only BGP routing dumps are here; in order to get AS connectivities you have to follow instructions and download and run several scripts).
Directions (AS relations) inferred using Lixin Gao's algorithm On Inferring Autonomous Systems R elationships in the Internet.
Recommend to take union of 5 days (possible collection failures). Recommend to ignore "SIBLINGS", or consider them bidirectional.
ASrelation.20010502.gz.
ASrelation.20010504.gz.
ASrelation.20010507.gz.
ASrelation.20010509.gz.
ASrelation.20010511.gz.

December 2001:
New data collection and inferrring AS relations maintained by by Lakshmi Subramanian, following the paper Characterizing the Internet Hierarchy from Multiple Vantage Points, INFOCOMM 2002.
The format is slightly different: Line "701 15290 1" means AS701 is a provider of AS15290. Line "701 1 0" means AS701 and AS1 are peers (bidirectional edge).
ASrelation.2001DEC.gz.

April 2002:
New data collection and inferrring AS relations maintained by by Lakshmi Subramanian, following the paper Characterizing the Internet Hierarchy from Multiple Vantage Points.
ASrelation.2002APRIL.gz.