Mirror/redirect action in tc(8)(<1/1a>Jan 2M0i1r5r)or/redirect action in tc(8)

     NAME
          mirred - mirror/redirect action

     SYNOPSIS
          tc ... action mirred DIRECTION ACTION [ index INDEX ]  dev
                  DEVICENAME

          DIRECTION := {  ingress | egress }

          ACTION := {  mirror | redirect }

     DESCRIPTION
          The mirred action allows packet mirroring (copying) or redi-
          recting (stealing) the packet it receives. Mirroring is what
          is sometimes referred to as Switch Port Analyzer (SPAN) and
          is commonly used to analyze and/or debug flows.

     OPTIONS
          ingress
               egress Specify the direction in which the packet shall
               appear on the destination interface.

          mirror
               redirect Define whether the packet should be copied
               (mirror) or moved (redirect) to the destination inter-
               face.

          index INDEX
               Assign a unique ID to this action instead of letting
               the kernel choose one automatically.  INDEX is a 32bit
               unsigned integer greater than zero.

          dev DEVICENAME
               Specify the network interface to redirect or mirror to.

     EXAMPLES
          Limit ingress bandwidth on eth0 to 1mbit/s, redirect exceed-
          ing traffic to lo for debugging purposes:

               # tc qdisc add dev eth0 handle ffff: ingress
               # tc filter add dev eth0 parent ffff: u32 \
                    match u32 0 0 \
                    action police rate 1mbit burst 100k conform-exceed pipe \
                    action mirred egress redirect dev lo

          Mirror all incoming ICMP packets on eth0 to a dummy inter-
          face for examination with e.g. tcpdump:

               # ip link add dummy0 type dummy

     Page 1                      iproute2            (printed 5/24/22)

     Mirror/redirect action in tc(8)(<1/1a>Jan 2M0i1r5r)or/redirect action in tc(8)

               # ip link set dummy0 up
               # tc qdisc add dev eth0 handle ffff: ingress
               # tc filter add dev eth0 parent ffff: protocol ip \
                    u32 match ip protocol 1 0xff \
                    action mirred egress mirror dev dummy0

          Using an ifb interface, it is possible to send ingress traf-
          fic through an instance of sfq:

               # modprobe ifb
               # ip link set ifb0 up
               # tc qdisc add dev ifb0 root sfq
               # tc qdisc add dev eth0 handle ffff: ingress
               # tc filter add dev eth0 parent ffff: u32 \
                    match u32 0 0 \
                    action mirred egress redirect dev ifb0

     SEE ALSO
          tc(8), tc-u32(8)

     Page 2                      iproute2            (printed 5/24/22)