Routing over Airport?

[Ashley Aitken]

Howdy All,

I'm back trying to route IP over Airport (not even bridging just  
routing).

I have two Macs A & B.

A has created a wireless network called W (using the Airport menu  
extra).
A has IP address 192.168.49.4
A has a static route 192.168.49 -interface en1
A has IP forwarding on
A also has a wired network connection elsewhere ...

nestat -nr shows:

Internet:
Destination        Gateway            Flags    Refs      Use  Netif  
Expire
default            192.168.1.1        UGSc       17       16    en0
127                127.0.0.1          UCS         0        0    lo0
127.0.0.1          127.0.0.1          UH         14    16341    lo0
169.254            link#4             UCS         0        0    en0
192.168.1          link#4             UCS         4        0    en0
192.168.1.1        0:50:7f:23:cf:be   UHLW       16        0    en0    
1198
192.168.1.2        0:c1:26:10:61:a6   UHLW        1      236     
en0    520
192.168.1.4        127.0.0.1          UHS         0       10    lo0
192.168.1.255      link#4             UHLWb       1      552    en0
192.168.20         192.168.1.2        UGSc        0        0    en0
vvvvvvvvvv
192.168.49         link#5             UCS         2        0    en1
192.168.49.4       127.0.0.1          UHS         0       38    lo0
192.168.49.7       link#5             UHRLW       4     4371     
en1     16
192.168.49.255     ff:ff:ff:ff:ff:ff  UHLWb       0        4    en1
^^^^^^^^^^

B has connected to the wireless network called W (using the Airport  
menu extra).
B has IP address 192.168.49.7 with router 192.168.49.4
B has a static route 192.168.49 -interface en1
B has IP forwarding on
B has a wired network connection to a printer ...

netstat -nr shows similar (but reversed, i.e. 4 and 7) for en1.

This is NOT using "Internet Sharing" (i.e. it is off).  I don't want  
the NAT that comes with that!

System preferences shows both machines are connected to the "Computer- 
to-Computer" network W.

Pinging the other machine from either side I get:

ping: sendto: Host is down
ping: sendto: Host is down
ping: sendto: Host is down
ping: sendto: Host is down
ping: sendto: Host is down
ping: sendto: Host is down
ping: sendto: No route to host
...

As Justin suggested before, I have used tcpdump for en1 (the wireless  
network) and get this:

18:46:43.826657 arp who-has 192.168.49.7 tell 192.168.49.4
18:46:44.949274 arp who-has 192.168.49.7 tell 192.168.49.4
18:46:45.950094 arp who-has 192.168.49.7 tell 192.168.49.4
18:46:47.074291 arp who-has 192.168.49.7 tell 192.168.49.4
18:46:48.075014 arp who-has 192.168.49.7 tell 192.168.49.4
18:46:57.361050 IP 192.168.49.4.ipp > 192.168.49.255.ipp: UDP,  
length: 113
18:46:59.448638 IP 192.168.49.4.ipp > 192.168.49.255.ipp: UDP,  
length: 129
18:47:02.463678 IP 192.168.49.4.ipp > 192.168.49.255.ipp: UDP,  
length: 94
18:47:03.528851 IP 192.168.49.4.ipp > 192.168.49.255.ipp: UDP,  
length: 146

And similar (but reversed, of course) on the other machine.  It looks  
like the ARP request is not getting out across the wireless network  
or the response is not getting back.

Can anyone suggest please what I may need to do?

I thought the wireless network would work just like an ethernet cable  
when connected and routing would then work as normal.

What am I missing?  Should this just work?

Thanks in advance.

Cheers,
Ashley.

--
Ashley Aitken
Perth, Western Australia
mrhatken at mac dot com
Skype Name: MrHatken (GMT + 8 Hours!)