Port Mirroring with Greenspan

The Mirroring features allows the mirroring of source port packets in Rx, Tx and both directions to a local destination port. Mirroring with Greenspan feature allows mirroring of source packets in Rx direction on to GRE tunnel.

Configuring Mirroring with Greenspan and Port

  • These commands configure a mirroring session with destination for GRE tunnel interface and regular port.


// Source port 
switch(config)#monitor session <name> source <interface> [ rx | tx | both ] [ ip access-group <access-list-name>

// GREENSPAN destination
switch(config)#monitor session <name> destination tunnel mode gre source <ipAddress> destination <ipAddress> ttl <ttlValue> dscp <dscpValue>

// Port destination
switch(config)#monitor session <name> destination <interface>


switch(config)#monitor session r1 source Ethernet2 rx ip access-group a3
switch(config)#monitor session r1 destination tunnel mode gre source destination

Displaying Mirroring with Greenspan and Port Information

These two commands display the monitor and platform related mirroring information.

  • show monitor session
  • show platform sfe mirroring


  • The show monitor session command displays the session information.

switch#show monitor session

Session r1

Programmed in HW: Yes

Source Ports:

Rx Only: Et2(IPv4 ACL: a3)

Destination Ports:

statussource destTTL DSCP protoVRF fwd-drop
Gre1 :active 128 0 0x88be default no
next hop interfaces: Et5 
  • The show platform sfe mirroring command displays the platform specific SFE mirroring information.

switch#show platform sfe mirroring
Session: r1, mirrorGroup: 3, globalId: 0
 srcIntf: Ethernet2, direction: Rx
 tgtIntf: Gre1
encapType: Gre
 Sfe module: Mir_r1_Rx_et2
Sfe srcIntf: Ethernet2, direction: Rx, gate: 0
Sfe tgtIntf: Ethernet5, gate: 1
Copy Success: 47523752, Fail: 0
Forward Success: 53109025, Fail: 0