phpman > man > tc-mirred(8)

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 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 desti‐
              nation interface.

       index INDEX
              Assign a unique ID to this action instead of letting the kernel choose  one  automati‐
              cally.  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 examination with e.g.  tcp‐
       dump:

              # 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)