Configuration

# 設定流量鏡像的來源為interface與目的地
en
conf t
    monitor session 1 source interface e0/0 both
    monitor seesion 1 source interface e0/1 tx
    monitor session 1 destination interface e1/0

    end
wr

# 設定流量鏡像的來源為vlan與目的地
en 
conf t
    monitor session 1 source vlan 100 both
    monitor session 1 destination interface e1/0

    end
wr

Check

show monitor session 1