Enabling FortiLink on an existing aggregate interface may alter its
behavior, as FortiGate will expect to manage FortiSwitches dynamically.
While Cisco switches should still pass traffic, VLAN handling might be
affected, so it's safer to configure Fo...
After you check the links and troubleshooting steps provided in the
previous reply, one likely cause of the issue could be Dead Peer
Detection (DPD) or keepalive issues. If the devices lose connectivity
even briefly, DPD might mark the peer as dead, ...
