Hi.
I have MikroTik RB750Gr3 , I flashed openwrt 24.10.0 into it. I'm trying to set up port mirroring for debugging and monitoring traffic using a computer with wireshark installed.
I read this topic: this
I saved the script to myself, with only the changes that I have
mirrorPort=lan5
Installed tc-full and ip-full packages
Doesn't work 
Outputs errors in ssh:
RTNETLINK answers: Not supported
We have an error talking to the kernel
RTNETLINK answers: Not supported
We have an error talking to the kernel
Tried step-by-step:
ip link set up dev lan5
worked without any messages
tc qdisc add dev wan clsact
Also worked without any messages
tc filter add dev wan ingress matchall skip_sw action mirred egress mirror dev lan5
And here is the error:
RTNETLINK answers: Not supported
We have an error talking to the kernel
following it
tc filter add dev wan egress matchall skip_sw action mirred egress mirror dev lan5
causes the same reaction
This method does not work.
Maybe the package port-mirroring will work?
https://openwrt.org/packages/pkgdata/port-mirroring
[https://github.com/mmaraya/port-mirroring]mmaraya/port-mirroring](https://openwrt.org/packages/pkgdata/port-mirroring)
I installed this software.
config:
/etc/config/port-mirroring
config 'port-mirroring'
option source_ports 'wan' # interfaces (maximum of 4) to copy packets from
option promiscuous '1' # put source interface(s) in promiscuous mode
option target 'lan5' # interface or IP address to send packets to
option protocol 'TEE' # 'TEE' iptables (default) or 'TZSP' TaZmen S
option filter '' # optional tcpdump/libpcap packet filter expr
Log:
logread |grep port-mirroring
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2104]: port-mirroring starting
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2104]: command-line argument[1]: --daemon
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2104]: command-line argument[2]: --syslog
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2104]: background process mode selected
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2104]: successfully read config file '/etc/config/port-mirroring'
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2133]: using process id 2133
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2133]: settings: src=wan dst=lan5 proto=TEE promisc=on filter=''
Mon May 19 20:13:53 2025 daemon.info port-mirroring[2133]: POSIX threads unavailable, running single-threaded
Doesn't work. Wireshark doesn't show any traffic from wan.
I'll try changing option source_ports to eth0 and reboot the device:
Mon May 19 20:38:20 2025 daemon.info port-mirroring[6150]: using process id 6150
Mon May 19 20:38:20 2025 daemon.info port-mirroring[6150]: settings: src=eth0 dst=lan5 proto=TEE promisc=on filter=''
Mon May 19 20:38:20 2025 daemon.info port-mirroring[6150]: POSIX threads unavailable, running single-threaded
Nothing interesting appeared.
Maybe I should set up a switch and somehow make mirroring on it?
I install the swconfig and kmod-swconfig packages:
swconfig list
doesn't display anything. Apparently, there is no switch support.
root@OpenWrt:~#cat /proc/cpuinfo
system type : MediaTek MT7621 ver:1 eco:3
machine : MikroTik RouterBOARD 750Gr3
So, the question is: How is it customary to solve such a problem on a router with MT7621 in 2025? 