This plugin will display informations about the last disconnected players.
https://forums.alliedmods.net/showthread.php?t=314886
sm_disconnections // Show the disconnections list
sm_disconnections_maxsize 15 // How many players will be shown in the disconnections list?
Disconnections List:
# Steam Name Ip Disconnected
01. STEAM_1:1:123456XX decoy 192.168.0.1 50s ago
02. STEAM_1:1:123456XY Ilusion9 192.168.0.1 3m ago
03. STEAM_1:1:123456YZ Fallen 192.168.0.1 1h 47m ago