[Techtalk] arp

[Raven, corporate courtesan]

Heya --

Quoth Jeff Dike (Mon, Oct 29, 2001 at 09:05:05PM -0500):
> One thing that other people have found necessary is to
> 	echo 1 > /proc/sys/net/ipv4/conf/DEVICE/proxy_arp
> 
> I've never figured out what that does, but it seems to fix some networking
> problems. 

	Basically, it turns on arp proxying if you have the ability to
do so compiled into your kernel.  Lots of the proc files (at least for
networking) are like this.  If the file contains 0, whatever is off.  If
the file contains 1, whatever is on.  So things like IP masquerading,
etc., usually require a similar step of echoing "1" to something like
/proc/sys/net/ipv4/ip_forward or /proc/sys/net/ipv4/ip_masq_debug (if
you're debugging).

	Often, these steps are hidden somewhere in the startup scripts,
so most users don't know they're going on.

	If you don't have a /proc/sys/net/ipv4/conf/[device]/proxy_arp,
you may not have it compiled into your kernel.

Cheers,
Raven

"Alex pages: I think you should act all jealous! "WHY DIDN'T YOU
  TELL ME YOU HAD A GIRLFRIEND!!"
 Alex pages: And then threaten to shave his car.                      
 Alex pages: Er, cat."
  -- Alex, on disclosure among friends