# Weird icmp situation



## marcosvbuzo (Aug 30, 2010)

Hi all.
I Have the following situation: 

_ A FreeBSD 8.1 box, ip address 192.168.0.1. Acting as router.
_ Two FreeBSD 8.1 boxes, ip addresses 192.168.0.2 and 192.168.0.3, running MPD and NAT for invalid ip adresses.

All these boxes are connected to a switch, the router is the gateway of the two other boxes.

Sometimes, a strange problem happen:

_ 192.168.0.1 can not ping 192.168.0.2.
_ 192.168.0.2 can not ping 192.168.0.1.

_ 192.168.0.1 can ping 192.168.0.3.
_ 192.168.0.3 can ping 192.168.0.1.
_ 192.168.0.2 can ping 192.168.0.3.
_ 192.168.0.3 can ping 192.168.0.1.

_ 192.168.0.2 can ping addresses that are routed by 192.168.0.1.

I've made some tests with arping, and when everything is working fine, I get the following results:


```
beavis# arping 192.168.0.1
ARPING 192.168.0.1
60 bytes from 00:10:18:71:1e:3e (192.168.0.1): index=0 time=13.547 msec
```


```
ike# arping 192.168.0.2
ARPING 189.44.192.2
60 bytes from b8:ac:6f:83:30:95 (192.168.0.2): index=0 time=13.643 msec
```

When things do not work, I get the following result on 192.168.0.2


```
beavis# arping 192.168.0.1
ARPING 192.168.0.1
arping: libnet_write(): libnet_write_link(): -1 bytes written (Address family not supported by protocol family)
```
PS: 192.168.0.x addresses are ficticious.

Does anybody have ideia what could it be ?

Thanks.


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## marcosvbuzo (Aug 30, 2010)

Some news here.. /var/log/debug.log shows me that:

```
Aug 26 10:13:57 beavis kernel: llinfo for 192.168.0.1
Aug 26 10:13:57 beavis kernel: arpresolve: can't allocate llinfo for 192.168.0.1
Aug 26 10:14:00 beavis last message repeated 953 times
Aug 26 10:14:00 beavis kernel: e: can't allocate llinfo for 192.168.0.1
Aug 26 10:14:00 beavis kernel: arpresolve: can't allocate llinfo for 192.168.0.1
Aug 26 10:14:02 beavis last message repeated 918 times
Aug 26 10:14:02 beavis kernel: arpres
Aug 26 10:14:02 beavis kernel: arpresolve: can't allocate llinfo for 192.168.0.1
Aug 26 10:14:33 beavis last message repeated 1138 times
Aug 26 10:14:46 beavis last message repeated 133 times
```


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## SirDice (Aug 30, 2010)

Make use of tcpdump(1).


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