Symptom
Cat9500 High Performance or Cat9600switches running in Stackwise Virtual pair leveraging 1G copper transceiver [GLC-T or GLC-TE] as Dual Active Detection link might exhibit the symptom that DAD link that was originally in UP state does not come UP again if the following sequence of events is done
1) 1G copper transceiver is used for DAD link on interface X
2) 1G copper transceiver is removed from this interface and some other 10G/25G transceiver is inserted into the same interface
3) this new 10G/25G transceiver is removed and original 1G copper transceiver is installed back
after these events 1G copper transceiver used as DAD link on the same interface where it originally was in UP state will remain in DOWN state
Conditions
Cat9500 High Performance SVL or C9600 SVL
GLC-T or GLC-TE used as DAD link
17.01.01 software release
Workaround
use fiber transceiver such as GLC-SX-MMD or GLC-LH-SMD for DAD link
upgrade to a software release where this problem is addressed
do not swap 1G copper transceivers to 10G/25G and back when that interface is designated for DAD link purposes
Further Problem Description
this issue is specific to 1G copper transceivers when used on DAD link
this does not affect 1G copper transceivers used for regular data link [not Dual Active Detection link]
