Hi Paul
Thanks for your reply. I have OSPF and BGP running, but for different purpose. The issue happens with the 2nd switch rebooting. When the first switch reboots, it doesn't impact the BGP peering on the 2nd one. But when the reverse happens, the 2nd switch is rebooted, all BGP peering on the other switch is also impacted.
I have a maintenance window planned, will do some more detailed investigation first for collecting more information.
Regards,
Sumanta.