• Welcome to Hurricane Electric's IPv6 Tunnel Broker Forums.

can traceroute find transit As?

Started by zhaojichang, April 21, 2008, 11:56:56 PM

Previous topic - Next topic


we use traceroute to discover the topo of ipv6 internet.After compare the data with the http://bgp.he.net/ipv6-progress-report.cgi?section=ases_v6&text=1,I found that in our datset we just have 433 AS numbers same as the  data publicated on the above page.
The data HE publicated came from BGP entries, so  I suspect may be it is about the way we use : traceroute, it can't find the transit As.
But I am not very sure. :-[
Any suggestion or advice is appreciated! :)
the data we cant' find can get from our web site:
http://ipv6.nlsde.buaa.edu.cn/upload/diff_with_hb_(dolphin not find).csv


Here are some basic questions (sorry if these are answered on your website):

How do you determine the specific IPv6 addresses you perform traceroutes to?

Are they related to the prefixes in the IPv6 global routing table?

From what router do you collect this "global routing table"?

Which ASes provide IPv6 BGP feeds to that collector router?

BTW, the "global routing table" is something of a misnomer, since any data is just a view from some vantage points.

In the case of the route-views data, it is from the perspective of all networks that provide a multihop BGP feed for data collection purposes.

How do you map prefixes to ASes?

Where does that data come from?


the paper we published may answer some of your questions, especially the paper about Dolphin,our topo discovery system.


The structure of the Dolphin System: :)


Here is a more specific answer for how to track down the difference.

Get an MRT parser written in C or perl.

Get a copy of the v6 MRT format RIBs from route views.

Make a script to dump the routes with path info found in the v6 MRT format RIB
into a text file, a route per line (like show ip bgp).

For each AS reported that you don't encounter in your dolphin data set,
grep for that AS in the text file.

All of the paths that show up tell you which prefixes and ASes are involved.

The first AS in the AS path is the AS that provided the data to route views.

(sorry if all of the above is obvious to you.)

In order for your traceroutes to cross all of the ASes missing from the dolphin data set,
the servers on which you do the traceroutes must be inside of networks with routes
that have AS paths that contain the missing ASes.

How many different networks (different ASes) do you have traceroute collectors in?


Thank you again!It sounds like a good idea. ::)
we have found 592 Ases ,and the destination adress pool:4625 entries.