nanog mailing list archives
Re: Ownership of Routers on Both Ends of Transnational Links
From: Pengxiong Zhu <pzhu011 () ucr edu>
Date: Tue, 16 Apr 2019 14:57:06 -0700
this is totally true :) but... if the next hop after chinaunicom-ic-341501-sjo-b21.c.telia.net is a CU ip... it's better than average chance that the chinaunicom-ic-341501-sjo-b21.c.telia.net address is a telia /30 (or /31) on the ptp link between CU/Telia. That Telia owns the ip space and that PROBABLY the customer identification is correct. (cu)
Yes, in our case, the next hops after all the six routers are some CU IPs. Best, Pengxiong Zhu Department of Computer Science and Engineering University of California, Riverside On Tue, Apr 16, 2019 at 2:34 PM Christopher Morrow <morrowc.lists () gmail com> wrote:
On Tue, Apr 16, 2019 at 5:19 PM Nimrod Levy <nimrod () nimrod is-a-geek net> wrote:On Tue, Apr 16, 2019, 16:52 Ross Tajvar <ross () tajvar io> wrote:I think it's clear that the IPs belong to Telia, but I understoodJames'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 ChinaUnicom in it, so that one is probably in use by China Unicom, and the other is probably in use by Telia.that was my point yes.I think we're making a lot of assumptions about how well PTR records aremaintained. All of this could be totally accurate. Or...not... this is totally true :) but... if the next hop after chinaunicom-ic-341501-sjo-b21.c.telia.net is a CU ip... it's better than average chance that the chinaunicom-ic-341501-sjo-b21.c.telia.net address is a telia /30 (or /31) on the ptp link between CU/Telia. That Telia owns the ip space and that PROBABLY the customer identification is correct. (cu) -chris
Current thread:
- Ownership of Routers on Both Ends of Transnational Links Pengxiong Zhu (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Ross Tajvar (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links James Jun (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Christopher Morrow (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Ross Tajvar (Apr 16)
- Message not available
- Re: Ownership of Routers on Both Ends of Transnational Links Christopher Morrow (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Pengxiong Zhu (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links James Jun (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Pengxiong Zhu (Apr 16)
- Re: Ownership of Routers on Both Ends of Transnational Links Ross Tajvar (Apr 16)