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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | COLOPHON |
Mirror/redirect action in tc(8) Linux Mirror/redirect action in tc(8)
mirred - mirror/redirect action
tc ... action mirred DIRECTION ACTION [ index INDEX ] dev DEVICENAME
DIRECTION := { ingress | egress }
ACTION := { mirror | redirect }
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.
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.
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
tc(8), tc-u32(8)
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 2017-07-05. 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)