Duplicate packets from ip address

[DAWOOD6283]

I am trying to figure out how to duplicate packets from an IOT device that send my electricity usage to a remote server. I am testing a local server I build and want to duplicate the packets the device sends. From the router it send traffic to port 80. I just want to duplicate and forward traffic from 109.169.55.159 to 192.168.1.50.

tcp	192.168.1.81	64873	109.169.55.159	80	TIME_WAIT
tcp	192.168.1.81	53611	109.169.55.159	80	TIME_WAIT
tcp	192.168.1.81	63397	109.169.55.159	80	TIME_WAIT
tcp	192.168.1.81	57259	109.169.55.159	80	TIME_WAIT
tcp	192.168.1.81	56818	109.169.55.159	80	TIME_WAIT

 

[ColinTaylor]

What router and which firmware version?

 

[DAWOOD6283]

I have an RT-68u, with 386.7_2 firmware

 

[ColinTaylor]

You can do with iptables on the RT-AC68U but you need to disable NAT acceleration otherwise it won't work. That will restrict your maximum download speed to probably less than 250Mbps. What is your current internet speed?

 

[DAWOOD6283]

I only get about 210Mbps, so good there.
I tried
iptables -t mangle -A PREROUTING -d 192.168.1.81 -j TEE --gateway 192.168.1.50
iptables -t mangle -A PREROUTING -s 192.168.1.81 -j TEE --gateway 192.168.1.50

but get an error

 

[ColinTaylor]

but get an error

What error?

Try changing the first iptables command to POSTROUTING

 

[SomeWhereOverTheRainBow]

You can do with iptables on the RT-AC68U but you need to disable NAT acceleration otherwise it won't work. That will restrict your maximum download speed to probably less than 250Mbps. What is your current internet speed?

Dont forget, the bulk of the routers CPU will be exhausted in the 250mbps transactions as well.

 

[DAWOOD6283]

RT-AC68U-58B0:/tmp/home/root# iptables -t mangle -A POSTTROUTING -d 192.168.1.81 -j TEE --gateway 192.168.1.50
iptables: No chain/target/match by that name.

 

[ColinTaylor]

typo: POSTTROUTING

P.S. Did you remember to load the module? (modprobe xt_TEE)

 

[DAWOOD6283]

Thanks,

Got it. Forgot to load modprobe