Folks, I've been playing quite a bit with code and testing.
One tool that I've produced is "blackhole6", which essentially works as follows: 1) It runs traceroute6 with no EHs (path6, actually), and records the path to the destination (PATH) 2) It runs traceroute6 with EHs (path6, actually), and find the last responding node (M) 3) Looks-up M in PATH. The dropping node is M+1. Additionally, it finds relevant AS info for each of the systems above. If you want to try it, just: $ git clone https://github.com/fgont/ipv6toolkit.git $ cd ipv6toolkit # make install clean And then run the tool as: # blackhole6 IPV6_ADDRESS If you run the tool against an AAAA corresponding to www.google.com, you get: fgont@satellite:~/code/ipv6toolkit/tools$ sudo blackhole6 2800:3f0:4002:801::1011 SI6 Networks IPv6 Toolkit v2.0 blackhole6: A tool to find IPv6 blackholes Destination IPv6 address: 2800:3f0:4002:801::1011 (AS15169 - GOOGLE - Google Inc.,US) Last resp. node (no EHs): 2800:3f0:4002:801::1011 (AS15169 - GOOGLE - Google Inc.,US) (12 hop(s)) Last resp. node (DO 8): 2001:1291:0:4b::b (AS16735 -COMPANHIA DE TELECOMUNICACOES DO BRASIL CENTRAL,BR) (7 hop(s)) Dropping node: 2001:1291:0:63::2 (AS16735 - COMPANHIA DE TELECOMUNICACOES DO BRASIL CENTRAL,BR) I guess the question is why the dropping node seems to be M+2 rather than M+1 (based on public information, I was expecting Google to be the folks dropping the EH-enabled IPv6 packets rather than the Brazilian company above)?. If you do a normal traceroute (path6 tool of the toolkit), the route is: fgont@satellite:~/code/ipv6toolkit/tools$ sudo path6 -d 2800:3f0:4002:801::1011 1 (2001:1291:2e6:1::1) 0.4 ms 0.2 ms 0.3 ms 2 (2001:1291:200:42e::1) 278.4 ms 236.3 ms 239.0 ms 3 (2001:1291:2::b) 239.3 ms 240.5 ms 239.3 ms 4 (2001:1291:2::a) 239.6 ms 240.5 ms 243.1 ms 5 (2001:1291:0:2::b) 239.5 ms 240.8 ms 239.5 ms 6 (2001:1291:0:d7::a) 246.6 ms 240.1 ms 240.9 ms 7 (2001:1291:0:4b::b) 244.3 ms 240.1 ms 240.3 ms 8 (2001:1291:0:63::2) 255.5 ms 254.0 ms 255.1 ms 9 (2001:4860::1:0:4f24) 257.8 ms 257.6 ms 261.4 ms 10 (2001:4860::1:0:e) 281.6 ms 280.5 ms 283.2 ms 11 (2001:4860:0:1::d8) 282.9 ms 285.3 ms 285.9 ms 12 (2800:3f0:4002:801::1011) 284.2 ms 282.5 ms 285.7 ms And with a DOH of 8 bytes, it is: fgont@satellite:~/code/ipv6toolkit/tools$ sudo path6 -d 2800:3f0:4002:801::1011 -u 8 1 (2001:1291:2e6:1::1) 1.0 ms 0.4 ms 0.4 ms 2 (2001:1291:200:42e::1) 319.0 ms 245.6 ms 248.8 ms 3 (2001:1291:2::b) 249.0 ms 237.1 ms 239.9 ms 4 (2001:1291:2::a) 320.7 ms 320.1 ms 316.7 ms 5 (2001:1291:0:2::b) 243.9 ms 243.4 ms 243.6 ms 6 (2001:1291:0:d7::a) 240.0 ms 246.3 ms 247.7 ms 7 (2001:1291:0:4b::b) 249.8 ms 241.6 ms 238.8 ms 8 () * * * 9 () * * * 10 () * * * 11 () * * * Clearly, M+1 (2001:1291:0:63::2) is still the Brazilian carrier, while M+2 (2001:4860::1:0:4f24) is Google, the folks I was expecting to be dropping the packets. Obviously, I don't care about this specific case... but probably is one on which we might have more insights than others. Thoughts? Thanks! Best regards, -- Fernando Gont SI6 Networks e-mail: fg...@si6networks.com PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492 -- Fernando Gont e-mail: ferna...@gont.com.ar || fg...@si6networks.com PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1