Re: [j-nsp] ISSU offlined mpc - why?
On Wed, 1 Sept 2021 at 20:35, Chuck Anderson via juniper-nsp wrote: > Eventually during the ISSU process, the line card software needs to be > upgraded. During that part, each line card goes offline one at a > time. If you have multiple line cards, design your network such that > redundant network paths are connected across different cards to > prevent a total outage when each line card is upgraded one-by-one. Disclaimer: I do not use ISSU nor do I plan to use it, it is complex and I've been hurt before with non-obvious failure modes after the box is left in an unknown state, this is vendor agnostic fear I have and I am currently not seeking help to overcome it. https://www.juniper.net/documentation/us/en/software/junos/high-availability/topics/topic-map/unified-issu-enhanced-mode.html Enhanced mode is an in-service software upgrade (ISSU) option available on MPC8E, MPC9E, and MPC11E line cards that eliminates packet loss during the unified ISSU process The changes in hardware that affect MPC behaviour are mostly the microcode that the lookup engines run, in trio these are collections of identical cores called PPE (packet processing engine). In theory we could put one PPE at a time out of service, and restart it with new ucode, until we're all done, having N-1/N of nominal PPS capacity during upgrade (I think EA has 96 PPE, so 98.95% during upgrade), And in fact this is what 'hyper mode' does, Trio has ucode compatible history of over a decade, without running hyper mode the PPEs are running the old +decade old collection of code, with hyper mode the PPEs are running new rewrite of the ucode. Newer hardware is hyper mode only, older hardware it is operator choice which generation of ucode to run. -- ++ytti ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] ISSU offlined mpc - why?
On Wed, Sep 01, 2021 at 09:44:08AM -0700, Mike via juniper-nsp wrote: > "Unified ISSU is supported with Junos OS Release 17.4R1 for MX Series > routers with MPC-3D-16XGE-SFPP" > > my expectations were that the card would stay online and there > would be little to no operational impact, but this clearly wasn't the > case. I am just wondering if anyone can tell me why this might have been > the case and in the future what steps I would need to take to ensure > this both otherwise stays on the air during a future software update? Eventually during the ISSU process, the line card software needs to be upgraded. During that part, each line card goes offline one at a time. If you have multiple line cards, design your network such that redundant network paths are connected across different cards to prevent a total outage when each line card is upgraded one-by-one. ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
[j-nsp] ISSU offlined mpc - why?
Hello, I did an issu upgrade on an MX240 with dual routing engines, going from 15.1R6 to 17.4R2, and I had reviewed the fine manuals particularly concerning advance steps to ensure nonstop routing and so forth. But during the upgrade (near the very end), the router did offline my MPC 3D 16x 10GE, resulting in loss of routing for 5 minutes. According to juniper in their docs that state that: "Unified ISSU is supported with Junos OS Release 17.4R1 for MX Series routers with MPC-3D-16XGE-SFPP" my expectations were that the card would stay online and there would be little to no operational impact, but this clearly wasn't the case. I am just wondering if anyone can tell me why this might have been the case and in the future what steps I would need to take to ensure this both otherwise stays on the air during a future software update? Thank you. Mike- ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
