Thanks for that informative — and civil — explanation. In my experience, packets can “drop out“ of ASIC processing under unexpected and unusual circumstances, resulting in high CPU loads. Hopefully escalation of the case works, and TAC discovers yet another bug that can be addressed in a firmware update. -mel via cell On Aug 2, 2025, at 9:35 PM, Ryan Hamel <ryan@rkhtech.org> wrote: Mel, The control plane receives 100% of the packets, providing the control plane policies allow it to. The control plane is likely connected to the ASIC via a mix of a PCI-E interface (providing the programming interface and an emulated NIC) and/or a specialized NIC port. If the CPU port is experiencing packet loss (my stance is very unlikely), that can be a separate discussion. I agree that an escalation is the appropriate response here, where TAC should try to reproduce the issue with Drew's config. Kind regards, Ryan Hamel ________________________________ From: Mel Beckman via NANOG <nanog@lists.nanog.org> Sent: Saturday, August 2, 2025 4:23 PM To: Tom Beecher <beecher@beecher.cc> Cc: nanog@lists.nanog.org <nanog@lists.nanog.org>; Mel Beckman <mel@beckman.org> Subject: Re: Cisco ASR9902 SNMP polling ... is interesting Caution: This is an external email and may be malicious. Please take care when clicking links or opening attachments. I’ll just let the incivility of you both stand. -mel On Aug 2, 2025, at 3:52 PM, Tom Beecher <beecher@beecher.cc> wrote: Mel- Saku did not call *you* any names. He called your *incorrect statements* in this thread 'bizzard drivel'. Which he is absolutely correct about. While your intentions may certainly have been to help, your statements here have been frankly dead wrong and did not accomplish that. Probably just want to take the L here. On Sat, Aug 2, 2025 at 5:34 PM Mel Beckman via NANOG <nanog@lists.nanog.org<mailto:nanog@lists.nanog.org>> wrote: Saku, What is actually appalling is that a member of NANOG calls “bizarre drivel” the honest and sincere attempts by other members to help identify the possible problem. There’s no cause to be uncivil, people can disagree without stooping to name-calling. -mel
On Aug 2, 2025, at 11:46 AM, Saku Ytti via NANOG <nanog@lists.nanog.org<mailto:nanog@lists.nanog.org>> wrote:
On Sat, 2 Aug 2025 at 21:02, Tom Beecher via NANOG <nanog@lists.nanog.org<mailto:nanog@lists.nanog.org>> wrote:
I don't have in depth knowledge of Cisco's SNMP implementations, or even the ASR platform specifically, but if Cisco TAC is telling you this is 'normal', they are completely full of shit, and you should click any and every 'escalate' button you can find.
This almost sounds like a default control plane DDOS policer / LPTS , something like that.
There are various complicated reasons for this, LPTS policer is unlikely culprit, but possible. Bug search will show various DDTS with poor SNMP performance outcome, most of them are unrelated to LPTS.
But absolutely correct, the right solution is to escalate. In common case this would be SE from your account team, who would fight for you internally.
It is appalling that OP came to nanog after correctly suspecting TAC is gaslighting them, some community member piled on with what can only be described as a bizarre drivel. -- ++ytti _______________________________________________ NANOG mailing list https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2F7KXUNRGFI5OEVSDEDU2OL5VMY5NBGQCV%2F&data=05%7C02%7Cryan%40rkhtech.org%7C935f5b9276c34753763108ddd21bb022%7C81c24bb4f9ec4739ba4d25c42594d996%7C0%7C0%7C638897738572035533%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=6ZnOfMhjhXcOW6xJQgBOLUTCz9tS4Uzyb8esw9zjkww%3D&reserved=0<https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/7KXUNRGFI5OEVSDEDU2OL5VMY5NBGQCV/>
NANOG mailing list https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2FCF3QHVTISL6LDFTOWG4E3KK54QEDHUIY%2F&data=05%7C02%7Cryan%40rkhtech.org%7C935f5b9276c34753763108ddd21bb022%7C81c24bb4f9ec4739ba4d25c42594d996%7C0%7C0%7C638897738572091179%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=rMHLcrZ21hVS2zLMHWW2nmH%2FZoF%2FPm3gZdU1ViywGQc%3D&reserved=0<https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/CF3QHVTISL6LDFTOWG4E3KK54QEDHUIY/> _______________________________________________ NANOG mailing list https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.nanog.org%2Farchives%2Flist%2Fnanog%40lists.nanog.org%2Fmessage%2FOJ7ICXLSPFND32X2XS2U7XIWA6DALSIF%2F&data=05%7C02%7Cryan%40rkhtech.org%7C935f5b9276c34753763108ddd21bb022%7C81c24bb4f9ec4739ba4d25c42594d996%7C0%7C0%7C638897738572130874%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=J8MV4YiEOgQROlfuT5ij7baERA6aF8bH0Tm%2Bg2%2FMKC0%3D&reserved=0<https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/OJ7ICXLSPFND32X2XS2U7XIWA6DALSIF/>