Configuring ERSPAN Mirroring

Do the following to configure ERSPAN Mirroring where the source port is a Physical Ethernet port and the destination ports are a RSPAN VLAN and another Physical Ethernet port.

Access global configuration mode.
```
SLX# configure terminal
```
(If necessary) Disable protocols on the destination interface.
This example disables LLDP.
1. Enter interface configuration mode.
```
SLX (config)# interface ethernet 0/2
```
2. Disable LLDP.
```
SLX (conf-if-eth-0/2)# lldp disable
                            
```
3. Exit interface configuration mode.
```
SLX (conf-if-eth-0/2)# exit
```

Create the port mirroring session and assign a number.

SLX (config)# monitor session 32
SLX (config-session-32)#

Identify the source Ethernet interface port, the destination port, and the direction of the traffic to monitor. Then create the appropriate mirroring configuration. The GRE tunnel is automatically created between the source and the destination ports.
```
SLX (config-session-32)# source ethernet 0/1 destination erspan 1 source-ip
                        10.10.10.1 destination-ip 10.20.20.1 vrf vrf-for-erspan direction both 
SLX (config-session-28)#
                    
```

The ingress traffic on ethernet port 0/1 will now be mirrored to the IP 10.20.20.1 over GRE tunnel.

This example summarizes the above configuration

SLX# configure terminal
SLX (config)# interface ethernet 0/3
SLX (conf-if-eth-0/3)# lldp disable
SLX (conf-if-eth-0/3)# exit
SLX (config)# monitor session 32
SLX (config-session-32)# source ethernet 0/1 destination erspan 1 source-ip 10.10.10.1 
        destination-ip 10.20.20.1 vrf vrf-for-erspan direction both

This example shows the configuration of ERSPAN mirroring from a source port channel port to a destination IP over GRE.

SLX (config)# monitor session 33
SLX (config-session-33)# source port-channel 1 destination erspan 1 source-ip 10.10.10.1 
        destination-ip 10.20.20.1 vrf vrf-for-erspan direction both

This example shows the configuration of ERSPAN mirroring from a VE (ve 1) to an specific destination IP(10.20.20.1). This traffic is directed over IP GRE tunnel with a source IP (10.10.10.1).

SLX (config)# monitor session 34
SLX (config-session-34)# source ve 1 destination erspan 1 source-ip 10.10.10.1 destination-ip 10.20.20.1
        direction rx vrf vrf-for-erspan flow-based
SLX (config-session-34)# exit

This example shows the configuration of ERSPAN mirroring from a VLAN (vlan 100) to an specific destination IP(10.20.20.1). This traffic is directed over IP GRE tunnel with a source IP (10.10.10.1).

SLX (config)# monitor session 34
SLX (config-session-34)# source vlan 100 destination erspan 1 source-ip 10.10.10.1 destination-ip 10.20.20.1
        direction rx vrf vrf-for-erspan flow-based
SLX (config-session-34)# exit