Thank you so much for your insightful replies. We are asking the right people! I checked the rest of them, they all seem to be /30 or /31s. 62.115.33.227 jax-b1-link.telia.net 62.115.33.228 telconet-ic-337544-jax-b1.c.telia.net 62.115.33.229 las-bb1-link.telia.net * 62.115.33.230 chinaunicom-ic-302366-las-bb1.c.telia.net 213.248.73.185 adm-b4-link.telia.net 213.248.73.186 riot-ic-303251-adm-b4.c.telia.net 213.248.73.187 213.248.73.188 213.248.73.189 sjo-b21-link.telia.net <http://sjo-b21-link.telia.net> * 213.248.73.190 chinaunicom-ic-127288-sjo-b21.c.telia.net. 152.179.103.250 0.xe-1-2-1.GW7.LAX1.ALTER.NET 152.179.103.250 chinaunicom-gw.customer.alter.net 152.179.103.251 152.179.103.252 152.179.103.253 0.xe-1-0-0.gw2.lax1.alter.net * 152.179.103.254 chinaunicom-gw.customer.alter.net. 63.243.205.89 ix-xe-0-3-3-0.tcore1.sqn-san-jose.as6453.net <http://ix-xe-0-3-3-0.tcore1.sqn-san-jose.as6453.net> * 63.243.205.90 63.243.205.91 63.243.205.92 63.243.205.93 ix-xe-8-2-5-0.tcore1.sqn-san-jose.as6453.net 66.110.59.117 ix-xe-2-1-3-0-0.tcore1.lvw-los-angeles.as6453.net * 66.110.59.118 66.110.59.119 66.110.59.120 66.110.59.121 ix-ae-2-611.tcore1.lvw-los-angeles.as6453.net How about the two IPs(63.243.205.90, 66.110.59.118) that don't have a reserve DNS name? Since they don't have any PTR records. Best, Pengxiong Zhu Department of Computer Science and Engineering University of California, Riverside On Tue, Apr 16, 2019 at 1:50 PM Ross Tajvar <ross@tajvar.io> wrote:
I think it's clear that the IPs belong to Telia, but I understood James's point to be that the router using the IP in question may belong to China Unicom. (I agree with that, I was not thinking clearly this morning.) As this is an interconnect link, one side must belong to Telia and the other to China Unicom. The question, then, is which side are we looking at? Well, first I want to know how big the subnet is. I assume either /30 or /31. So, I do a reverse DNS lookup on all the IPs in the surrounding /30 block: 62.115.170.56 - sjo-b21-link.telia.net 62.115.170.57 - chinaunicom-ic-341501-sjo-b21.c.telia.net 62.115.170.58 - las-b24-link.telia.net 62.115.170.59 - chinaunicom-ic-341499-las-b24.c.telia.net That looks like two /31s. Only one IP in each has the name of China Unicom in it, so that one is probably in use by China Unicom, and the other is probably in use by Telia.
On Tue, Apr 16, 2019, 3:50 PM Christopher Morrow <morrowc.lists@gmail.com> wrote:
On Tue, Apr 16, 2019 at 10:59 AM James Jun <james.jun@towardex.com> wrote:
More likely, thease routers are China Unicom's routers in their US POP, not managed by VZ/Telia. The /30s in this case are unmanaged IP transit hand-offs, coming in as Nx10G or 100G. When your IP transit provider assigns the /30, your router looks like it belongs to your upstream, common mistake when interpreting traceroutes[1].
$ nslookup 62.115.170.56 56.170.115.62.in-addr.arpa name = sjo-b21-link.telia.net.
if you model (as james says) each interconnect as a /30 or /31 ... look for the adjacent ip and see the PTR for that ip. (the above is your first link example's peer ip)
[1]: see Page 22 on https://www.nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N...
James