Re: [uml-user] UML w/ 2.4.10 Tun/Tap ARP issue

[Tim R. <ti...@tr...>]

> Well, making an observation from another connectivity scheme, pppd
> has to have proxy_arp turned on on all it's ppp-interfaces if you want to
> use IP's from the same network your main interface is on. Not sure if that

This seems like a good analogy.  pppd commonly brings up
IP interfaces in point-to-point mode from a netmask perspective,
not unlike the way that uml_net initializes the TUN/TAP interface.

Proxy arp is a stand in where ethernet "layer 2" broadcasting doesn't
reach a node that it otherwise would based upon the netmask.  I
would think that using it on the tap0 interface to reveal systems on
the other side of the uml host would imply a netmask issue on the
uml virtual machine's eth0.  Unless... setting proxy arp for a ppp or tap
interface has a special connotation, e.g. relay arp requests seen
here "to the other side".

Out of curiosity, what netmask is the eth0 on the uml box(es) using?
I started to look into modifying the eth0 ifconfig that is implemented
by the uml box so that it would have a netmask of 255.255.255.255.
Doing so would force all "layer 3" IP traffic via the uml host, this
would complete the TUN/TAP and pppd analogy.  My first try didn't
work, but then, I didn't think to set proxy_arp on my tap0 i/f  ;-)

-Tim