NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | COLOPHON

Mirror/redirect action in tc(8)     Linux    Mirror/redirect action in tc(8)

NAME         top

       mirred - mirror/redirect action

SYNOPSIS         top

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

       DIRECTION := { ingress | egress }

       ACTION := { mirror | redirect }

DESCRIPTION         top

       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         top

       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         top

       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. 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         top

       tc(8), tc-u32(8)

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling TCP/IP
       networking and traffic) project.  Information about the project can
       be found at 
       ⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
       If you have a bug report for this manual page, send it to
       netdev@vger.kernel.org, shemminger@osdl.org.  This page was obtained
       from the project's upstream Git repository 
       ⟨git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git⟩
       on 2017-04-25.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-to-
       date source for the page, or you have corrections or improvements to
       the information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

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