Dist01.tor1 & Dist02.tor1 scheduled maintenance - 10-Nov-2023

[porcupine]

Hi Folks,

Please be advised of the following maintenance window:

Maintenance Window: Friday November 10th 2023, 11:00pm - 2:00am Eastern time
Facility: Tor1
Affected Device(s): dist01.tor1, dist02.tor1
Affected Customers: Customers connected to either dist01.tor1 or dist02.tor1
Service Impacting: No - We do not expect this to be a service impacting maintenance, this is a precautionary notice only.

Details: We will be adding secondary supervisor line-cards to the dist01.tor1 and dist02.tor1 distribution switches/routers, with the intent of operating both units in high availability, aka Stateful Switch Over (SSO) mode going forward. This additional hardware redundancy should allow the distribution switches/routers to handle internal software and/or hardware failures more gracefully, typically failing over to the secondary supervisor card in the event of an issue, instead of rebooting the entire chassis (reducing the impact of such an event to 0-3 seconds, as opposed to 5-15 minutes).

We have already removed all customers from the existing line-card where the secondary supervisor needs to be installed, and the procedure has already been tested/practised before on both spare equipment, and as an upgrade that was previously performed in the Tor2 facility.

We will be starting with dist02.tor1, and only moving onto dist01.tor1 once dist02.tor1 has completed its upgrade in full.

While we do not expect this to be a service impacting event, given both units have extensive uptimes (dist01.tor1 is at nearly 2 years of uptime, and dist02.tor1 is nearing 4 years), we recognize that when adding/removing cards from supervisor slots, and making significant hardware changes, anything can happen -- hence the precautionary maintenance window.

If everything goes according to plan, the maintenance on each device should only take a small fraction of the scheduled window.