Subject: ppp proxyarp problem
To: None <current-users@NetBSD.ORG>
From: maximum entropy <entropy@zippy.bernstein.com>
List: current-users
Date: 12/18/1997 06:38:07
Hi,

tardis is an i386 running 1.3_ALPHA.
seki is an atari running 1.3_BETA.

tardis has a SLIP link to the outside world (on tty00), and a network
card to my local net.  A second serial port (tty01) has a dedicated
PPP link to seki, with the proxyarp option set.  tardis's default
route is through sl0.

seki has a PPP link (on serial2) to tardis with the defaultroute
option set.

Everything works fine for the most part.  However, if I reboot seki,
sometimes the proxy entry in the arp cache on tardis isn't deleted.
When seki comes back up and tries to reestablish the ppp session, I
get:

Dec 17 03:16:03 tardis pppd[24441]: Couldn't set interface address: Address 206.20.83.195 already exists
Dec 17 03:16:03 tardis pppd[24441]: found interface ep0 for proxy arp
Dec 17 03:16:03 tardis pppd[24441]: local  IP address 206.20.83.195
Dec 17 03:16:03 tardis pppd[24441]: remote IP address 206.20.83.203

...and the PPP link is nonfunctional.  If I kill pppd on tardis, then
"arp -d seki", and restart pppd, all is well again.

It seems that this only happens if seki has open network connections
when it is rebooted.

Configuration info:

tardis:/etc/ppp/peers/seki :
tty01 38400
noauth
crtscts
nodefaultroute
206.20.83.195:206.20.83.203
local
persist
proxyarp

seki:/etc/ppp/peers/tardis :
ser02 38400
noauth
crtscts
defaultroute
206.20.83.203:206.20.83.195
local
persist
noproxyarp

Is this a configuration problem or a bug?

Cheers,
entropy

--
entropy -- it's not just a good idea, it's the second law.