[ale] Proxy ARP

[Christopher Fowler]

I'm trying to configure ProxyARP to work on a remote machine.  I want
the remote server to appear as a node on my local network.


Local ---------------------------------------------------
eth0:  192.168.3.1 Netmask: 255.255.255.0
ppp0      Link encap:Point-to-Point Protocol  
          inet addr:192.168.3.1  P-t-P:192.168.3.107   
          Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1400  Metric:1
          RX packets:9 errors:0 dropped:0 overruns:0 frame:0
          TX packets:9 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:366 (366.0 b)  TX bytes:472 (472.0 b)


Remote --------------------------------------------------
ppp0      Link encap:Point-to-Point Protocol  
          inet addr:192.168.3.107  P-t-P:192.168.3.1    
          Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1400  Metric:1
          RX packets:61 errors:1 dropped:0 overruns:0 frame:0
          TX packets:47 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:6212 (6.0 Kb)  TX bytes:5699 (5.5 Kb)



Trace Route from a machine on my network:
[root at skylab root]# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:60:08:CE:36:1E  
          inet addr:192.168.2.254  Bcast:192.168.2.255
Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2388129 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1450371 errors:0 dropped:0 overruns:0 carrier:9767
          collisions:0 txqueuelen:100 
          RX bytes:277413242 (264.5 Mb)  TX bytes:463889425 (442.3 Mb)
          Interrupt:9 Base address:0xb800 

[root at skylab root]# traceroute 192.168.3.107
traceroute to 192.168.3.107 (192.168.3.107), 30 hops max, 38 byte
packets
 1  192.168.3.1 (192.168.3.1)  0.433 ms  0.383 ms  0.280 ms
 2  *



It appears that 192.168.3.1 is picking up the packet for 192.168.3.107.
But 192.168.3.107 only knows where 192.168.3.1 is.  It has no clue how
to get the packet back to 192.168.3.254

Based on this from the remote:
[tomcat at sam-service tomcat]$ traceroute 192.168.3.254
traceroute to 192.168.3.254 (192.168.3.254), 30 hops max, 38 byte
packets
 1  gtwy8-atlanta.netriplex.com (209.168.246.193)  0.889 ms  0.661 ms
0.731 ms
 2  suwC4-gig7-1-4.edeltacom.com (216.154.207.93)  0.854 ms  0.709 ms
0.604 ms
 3  suw03-gig4-2.edeltacom.com (216.154.207.90)  0.479 ms  0.341 ms
0.357 ms
 4  gig5-2.suwangaeq00w.cr.deltacom.net (66.35.174.137)  0.479 ms  0.342
ms  0.358 ms
 5  pos5-0.atlngapk22w.cr.deltacom.net (66.35.174.101)  1.979 ms !H


My guess is that I need to add the following to the remote to make it
work:

route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.3.1


The reason why I ask is that normally when I setup a  Linux PPP server
and have Windows DUN I don't have to worry about that.  I guess because
Windows DUN automatically adds a default route and in my case it is only
a 255.255.255.255 connection.  Unfortunately it seems that the mask
option has been deprecated from the newer versions of pppd.