[ILUG] Proxy arp problems

[Dave Airlie]

echo 1 > /proc/sys/net/ipv4/conf/all/proxy-arp

don't know if it helps but I find myself doing it regualrly enough with my
IR link... 

Dave.

On Fri, 10 Mar 2000, Kenn Humborg wrote:

> 
> I've got a machine atlas.bluetree.ie, with a pppd listening on
> one of the serial ports, connected to a Palm V.  The pppd
> hands out the address dialup-0.bluetree.ie to the remote
> device.
> 
> This is the pppd command line:
> 
>    /usr/sbin/pppd ttyS0 57600 -detach proxyarp \
>       passive local crtscts lock :dialup-0
>       noauth ms-dns atlas
> 
> 
> Before I connect from the Palm, the arp cache has no entry
> for dialup-0.  After I connect from the Palm, arp -a shows:
> 
> [root at atlas /root]# arp -a...
> dialup-0.bluetree.ie (192.168.3.250) at * PERM PUP on eth0
> [root at atlas /root]#
> 
> This doesn't look right.  If I try to ping dialup-0 from
> another machine, the other machine gets this entry in its
> arp table:
> 
> [root at cerberus /root]# arp -a
> Address                 HWtype  HWaddress           Flags Mask
> Iface
> ...
> dialup-0.bluetree.ie    ether   00:00:00:00:00:00         *
> eth0
> [root at cerberus /root]#
> 
> This definitely isn't right.  When I disconnect from the Palm,
> the arp entry is removed from atlas, as expected.
> 
> So let's try manually adding the arp entry:
> 
> [root at atlas /root]# arp -s dialup-0 00:40:95:01:77:1B
> [root at atlas /root]# arp -a
> dialup-0.bluetree.ie (192.168.3.250) at 00:40:95:01:77:1B [ether] PERM on
> eth0
> ...
> 
> But that won't get published to other machines.  So let's try
> deleting this entry and adding a pub entry:
> 
> [root at atlas /root]# arp -a
> dialup-0.bluetree.ie (192.168.3.250) at <incomplete> on eth0
> ...
> dialup-0.bluetree.ie (192.168.3.250) at * PERM PUP on eth0
> [root at atlas /root]#
> 
> What the hell is going on here?
> 
> RH6.0, net-tools-1.52-2
> 
> Later,
> Kenn
> 
> 
> 

-- 
------------ David Airlie, David.Airlie at ul.ie,airlied at skynet --------
Telecommunications Research Centre, ECE Dept, University of Limerick \
http://www.csn.ul.ie/~airlied	-- Telecommunications Researcher      \
--- TEL: +353-61-202695 -----------------------------------------------