Symptom
On CAT8500 series the configuration of 'negotiation auto' is supported when a 1G SFP is inserted into one of the interfaces.
When a CAT8500 is running IOS-XE SDWan version : 17.3.4a and has 'negotiation auto' configured on an interface which has a 1G SFP inserted upon reload there will be a mismatch between confd and ios.
The confd (SDWan) configuration will show 'negotiation auto' under the interface
The ios configuration will be reverted to the default 'no negotiation auto' under the interface
Depending on what is connected on the opposite end this may result in an outage that will not be recovered until the configuration is put back into sync.
Conditions
CAT8500 running 17.3.4a IOS-XE SDWan software that has 'negotiation auto' configured under an interface which has a 1G SFP inserted.
Workaround
This is done by configuring the following on the impacted interface :
config-t
interface TenGigabitEthernet x/x/x
no negotiation auto
comm
negotiation auto
comm
Use IOS-XE SDWan version : 17.3.3
Further Problem Description
The same symptom is not present on : 17.3.3
If negotiation auto is configured on an interface with a 1G SFP configuration will remain in sync after reboot.
