Single Dual-Active-Detection Link to ePAgP Dual-Active-Detection

[absuizo14]

we are planning to change our C9606R-48Y24C-BN-A current 1g single DAD link into 10g(overkill in my opinion but client insisted) dual DAD link via ePAgP. here are some questions that we need to address.

-my question is how do we go about this with the least amount of downtime?

-should i disable Recovery Reload before doing anything?

[MHM Cisco World]

Detection mechanisms and configuration

Because of the challenges of distinguishing a remote switch power failure from a StackWise Virtual link failure, each switch attempts to detect its peer switch, in order to avoid the dual-active scenario. In a dual-active scenario, it must be assumed that the StackWise Virtual link cannot be used in any way to detect the failure. The only remaining options are to use alternative paths that may or may not exist between the two chassis.

Currently, there are two mechanisms for detecting a dual-active scenario:

●      Fast Hello

●      Enhanced PAgP

Products - Cisco Catalyst 9000 Platform StackWise Virtual White Paper - Cisco

no need separate DAD link you can use ePAGP instead check link above

MHM

[absuizo14]

Good to know but we are not planning to change the logical setup of our current core switches so lets just stick to physically separate SVL and DAD links

[absuizo14 · Accepted solution]

Update on this topic:

we ended up using fast hello instead since  we are using 2 100gig links for SVL and 2 10gig links for DAD. ePAGP requires you to EtherChannel both the SVL and DAD links together and since we are using different speeds for those links ePAGP is not possible. 

Regarding my questions here are what i have observed:

-my question is how do we go about this with the least amount of downtime?

everytime you change a config on an already working SVL or DAD link you have to restart the switch for it to take effect which means, when i removed the config from the ports i had to restart the switch and when it came up and added the config i also had to restart the switch 

-should i disable Recovery Reload before doing anything?

no need since you will have to restart the switch anyway and this feature only reloads the active switch if both the DAD and SVL links are down and come back up.