How can I monitor arp traffic on the WAN?

Installing and Using OpenWrt
1

Hi,

I have a network connected to CGNAT and I’m trying to figure out why I am getting moments where traffic stops being router ?

I suspect on the WAN side I’m getting some ARP issues, so I’d like to run some software to make sense of all the arp messages and monitor the status of the arp table and maybe figure out why things occasionally get misconfigured ?

I’ve found arp-scan and arp-whisper but I can’t figure out how to use them. arp-whisper needs a config file to work ?

And all I could search was for package with “arp” in the package name. Are there better utilities to monitor ARP and makes sense of what is going on ?

2

Install ip-full and use IP monitor. You can also verify the neighbor table with IP neighbor.

3

If i undesrtand you concern try this:
tcpdump -i wan arp

With that I get all arp traffic, not just mine but requests of other ISP customers with that command.

4

How do you know you jave ARP issues without monitoring it?
You can use arptables-nft to log count filter arp traffic