Networking problem

[Tom H]

On Sun, May 15, 2011 at 1:39 AM, JD <jd1008 at gmail.com> wrote:
> On 05/14/11 22:02, Shane Dawalt wrote:
>>
>> Usually, firewalls don't inhibit ARP entries. To test this theory,
>> try "ping 192.168.1.70" from your 192.168.1.108 box.  Directly after
>> that, issue the command "arp -a".  If ARP works, you should see
>> something like this.
>>
>> ? (10.1.1.1) at 00:30:ab:13:9e:3d [ether] on eth0
>>
>> (On my net, 10.1.1.1 is my gateway.)  If it doesn't work, you'll see
>> something like this:
>>
>> ? (10.1.1.253) at<incomplete>  on eth0
>>
>> where 10.1.1.253 is a non-existent machine on my network.  And you'll
>> see ping responses such as these:
>>
>> PING 10.1.1.253 (10.1.1.253) 56(84) bytes of data.
>>   From 10.1.1.21 icmp_seq=2 Destination Host Unreachable
>>   From 10.1.1.21 icmp_seq=3 Destination Host Unreachable
>>   From 10.1.1.21 icmp_seq=4 Destination Host Unreachable
>>
>>  You've already posted something like this, so it's a good bet ARPs
>> aren't working.  So the wireless router is a good bet at this point.
>>
>>     Shane
> On the Fedora Machine:
> # arp -a
> ? (192.168.1.254) at 0:1d:1a:00:91:c1 [ether] on wlan0
>
> On the PowerBook Machine:
> # arp -na
> ? (192.168.1.1) at 0:28:fe:6:ef:7 on en1 [ethernet]
> ? (192.168.1.108) at (incomplete) on en1 [ethernet]
> ? (192.168.1.254) at 0:1d:1a:00:91:c1 on en1 [ethernet]
> ? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en1 [ethernet]
>
> Now this is really strange!
> Fedora's arp reports only the gateway!
> Whereas PowerBooks arp reports the gateway, the wired machine
> 192.168.1.1 and even the Fedora machine it cannot ping: 192.168.1.108

The PowerBook doesn't report the MAC address of 192.168.1.108 (as
Shane expected) because it prints the MAC address as "(incomplete)" -
confirming that your pings aren't reaching your Fedora box.