Hi, First off, apologies if I'm completely lost. I'm not a network professional of any kind, just a random with a question I can't find the answer to on the internet. Basically, I was poking around on this website called bgp.tools and many ASN have a page describing BGP communities known by the network, e.g. https://bgp.tools/communities/13335. It includes descriptions for each one:
13335:10106 PoP: bos01 13335:10358 PoP: cwb03 13335:10712 PoP: den04 13335:10766 PoP: maa05 13335:10920 PoP: zrh02 [...]
I want to know, where does this supplementary information about the communities come from, in this case the "PoP: blah" bits? I don't think it is communicated by BGP directly, so is there some standard out of band mechanism to describe the communities? Or am I just ignorant of this BGP feature? The background is that I live in AZ, USA, and am I subscribed to Cox for my internet service. I noticed that my ping to "example.com" (literally) is slower on IPv6 compared to IPv4: $ ping -4 example.com PING example.com (104.18.27.120) 56(84) bytes of data. 64 bytes from 104.18.27.120: icmp_seq=1 ttl=251 time=9.58 ms 64 bytes from 104.18.27.120: icmp_seq=2 ttl=251 time=5.94 ms 64 bytes from 104.18.27.120: icmp_seq=3 ttl=251 time=7.76 ms 64 bytes from 104.18.27.120: icmp_seq=4 ttl=251 time=6.85 ms [...] $ ping -6 example.com PING example.com (2606:4700::6812:1b78) 56 data bytes 64 bytes from 2606:4700::6812:1b78: icmp_seq=1 ttl=57 time=20.0 ms 64 bytes from 2606:4700::6812:1b78: icmp_seq=2 ttl=57 time=19.0 ms 64 bytes from 2606:4700::6812:1b78: icmp_seq=3 ttl=57 time=20.8 ms 64 bytes from 2606:4700::6812:1b78: icmp_seq=4 ttl=57 time=19.8 ms [...] $ traceroute -IAen4 -z1 example.com traceroute to example.com (104.18.26.120), 30 hops max, 60 byte packets 1 10.3.0.254 [*] 0.249 ms 0.361 ms 0.362 ms 2 10.40.160.1 [*] 8.978 ms 8.658 ms 7.745 ms 3 100.127.73.232 [*] 6.957 ms 8.557 ms 6.881 ms 4 68.1.0.187 [AS22773] 8.067 ms 10.434 ms * 5 184.183.131.9 [AS22773] 13.818 ms 37.728 ms 17.832 ms 6 162.158.140.23 [AS13335] 16.822 ms 8.761 ms 16.768 ms 7 104.18.26.120 [AS13335] 8.813 ms 7.852 ms 9.451 ms $ traceroute -IAen6 -z1 example.com traceroute to example.com (2606:4700::6812:1b78), 30 hops max, 80 byte packets 1 2600:8800:1780:c000::1 [AS22773] 0.315 ms 0.360 ms 0.362 ms 2 2600:8800:17ff:ffff::1111 [AS22773] 6.601 ms 24.911 ms 9.655 ms 3 2001:578:800:6:8100::818 [AS22773] 31.164 ms 8.727 ms 9.075 ms 4 2001:578:900:4::2 [AS22773] 8.763 ms 7.661 ms 6.873 ms 5 2001:578:1:0:172:17:249:32 [AS22773] 29.991 ms 35.838 ms 19.517 ms 6 2001:578:20:a000::7:1 [AS22773] 21.781 ms 20.676 ms * 7 2400:cb00:12:3:: [AS13335] 20.474 ms 20.099 ms 19.824 ms 8 2606:4700::6812:1b78 [AS13335] 20.078 ms 19.747 ms 20.788 ms It's not really a problem, but still I just want to know... why? I thought it would be kind of odd to have example.com hosted only on IPv4 in the Phoenix area so I was trying to see if I could determine whether or not that was the case looking at https://bgp.tools/communities/13335?show-prefixes=13335%3a10066, but I think there just simply isn't enough information available online for me to find out. Thanks, Ronan