Hello,

I noticed that our freewrt routers answer to arp request for ip adresses on 
all available interfaces, even if the requested ip is not bound to the 
interface where the request was recieved. This has nothing to do with vlans, 
furthermore this happens even for completely diffrent physical interfaces.

in my case the IP 192.168.1.1 was configured on eth0.6, but even if I pinged 
192.168.1.1 from an external system, that was connected to eth0.0, the box 
replied via arp on eth0.0, even if the ip isn't reachable via eth0.0 at all. 

This means that it is not possible to use the same IPs in diffrent VLANs or 
physical LANs at all without serious trouble.

To disable this "feature" of arp-replying on all interfaces, it is possible to 
set arp_filter = 1 via the proc interface per interface or global for all 
interfaces.

Even if the default linux behaviour is to repsond to arp request on all 
interfaces (arp_filter = 0) it might be more clever to enable this filter on 
all freewrt installations per default. It shouldn't break anything on a 
already working setup, but should help to reduce strange network errors that 
are hard to resolve, that might get caused without this filter.

Waldemar told me, that he would like to enable this filter globally, so if no 
one protests about it, we will enable it for branch/1.0 in 5 days from now 
on.

bye,
 Ralph
_______________________________________________
freewrt-developers mailing list
[email protected]
https://www.freewrt.org/lists/listinfo/freewrt-developers

Reply via email to