I've seen "grey failure" issues like this a few times with Cogent in the south. There will be an issue on their backbone somewhere, and they'll continue to advertise our prefixes and blackhole our traffic. Is this because they've got some kind of setup where their control plane is separated from their data plane, so that their iBGP peers stay up when there's no path for the data to take to the site? Or is it a lack of failover capacity and extreme congestion, where enough traffic is able to get through that their iBGP sessions stay up, but best-effort customer traffic is getting tossed on the floor? On Tue, Nov 25, 2025 at 8:34 PM Michael J McCafferty via NANOG < nanog@lists.nanog.org> wrote:
Can confirm we are affected in Austin. We have pulled the plug to Cogent until it recovers. Sent from my Galaxy -------- Original message --------From: Robert DeVita via NANOG < nanog@lists.nanog.org> Date: 11/25/25 4:49 PM (GMT-08:00) To: North American Network Operators Group <nanog@lists.nanog.org> Cc: nanog@lists.nanog.org, Robert DeVita <radevita@mejeticks.com> Subject: Re: internet - at least texas Dear Cogent Customer,We are currently experiencing an outage on our network. We are working to resolve this as quickly as possible. Please for updates on this event.If you need to open an individual ticket on this event, please e-mail support@cogentco.com and reference outage HD305673827.Impacted Region: Texas, USA / MexicoOrder(s) Impacted: 1-300427262Outage Ticket: HD305673827Status:Get Outlook for iOS<https://aka.ms/o0ukef>________________________________From: Tim Burke via NANOG <nanog@lists.nanog.org>Sent: Tuesday, November 25, 2025 5:25:08 PMTo: nanog@lists.nanog.org <nanog@lists.nanog.org>Cc: nanog@lists.nanog.org <nanog@lists.nanog.org>; Tim Burke <tim@mid.net>Subject: Re: internet - at least texasNo issues here in Houston or Dallas on cogent. Not seeing any complaint volume on outages list, either. May be localized.> On Nov 25, 2025, at 17:32, Aaron Gould via NANOG <nanog@lists.nanog.org> wrote:>> what in the world is going on in texas? i'm in south texas (san antonio) and all 4 of my internet connections went way down! i disabled cogent bgp and already looking better on my other transit links (non-cogent)>> --> -Aaron>> _______________________________________________> NANOG mailing list https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2F3KIJECRT6TZWEICWHLH4G4DSY4BXXW6L%2F&data=05%7C02%7Cradevita%40mejeticks.com%7Ce8738236aec24220fd7f08de2c824a23%7Cf4cf98f2d77845638d5b5fd2fa70ff2f%7C0%7C0%7C638997135290815962%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=43PT9%2FQZjUc5gYf8dlwn4%2FYgrbmUwnCMVNOh43a1mU8%3D&reserved=0 < https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/3KIJECRT6TZWEICWHLH4G4DSY4BXXW6L/>_______________________________________________NANOG mailing listhttps:// nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2FQ5SJZNSAVV735EGV7OSF43HJ5RKDRH2E%2F&data=05%7C02%7Cradevita%40mejeticks.com%7Ce8738236aec24220fd7f08de2c824a23%7Cf4cf98f2d77845638d5b5fd2fa70ff2f%7C0%7C0%7C638997135290836571%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=8py0AgliuL0NtteKqQUlb3lors1Mkkf%2BqMD6DDyuTK0%3D&reserved=0 < https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/Q5SJZNSAVV735EGV7OSF43HJ5RKDRH2E/>_______________________________________________NANOG mailing list https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/TRP7DGXI... _______________________________________________ NANOG mailing list
https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/VAINR3HY...