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 < [email protected]> 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 < > [email protected]> Date: 11/25/25 4:49 PM (GMT-08:00) To: North > American Network Operators Group <[email protected]> Cc: > [email protected], Robert DeVita <[email protected]> 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 [email protected] > 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 <[email protected]>Sent: Tuesday, November 25, > 2025 5:25:08 PMTo: [email protected] <[email protected]>Cc: > [email protected] <[email protected]>; Tim Burke > <[email protected]>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 <[email protected]> > 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/[email protected]/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/[email protected]/message/Q5SJZNSAVV735EGV7OSF43HJ5RKDRH2E/>_______________________________________________NANOG > mailing list > https://lists.nanog.org/archives/list/[email protected]/message/TRP7DGXITZTUMYAZIH2Z53BR4F3WO5C4/ > _______________________________________________ > NANOG mailing list > > https://lists.nanog.org/archives/list/[email protected]/message/VAINR3HYHSOVAXV3M7YNNAEPGBRYUXFE/ _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/JHL6GUAKXVLZ7QRSUY52VWC74DP7P4BW/
