tc-mirred

Mirror/redirect action in tc(8)      Linux     Mirror/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 redirecting
       (stealing) the packet it receives. Mirroring is what is  sometimes  re-
       ferred  to  as Switch Port Analyzer (SPAN) and is commonly used to ana-
       lyze 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 interface.

       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 exceeding  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 interface for exam-
       ination with e.g. tcpdump:

              # ip link add dummy0 type dummy
              # 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 traffic  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)

iproute2                          11 Jan 2015  Mirror/redirect action in tc(8)