Unexpected behaviors connectivity FreeBSD

[Luca Da Col]

We have a FreeBSD 6.2 System connected to our DMZ used to store periodical
informations about our network. FreeBSD is showing some unexpected behaviors
loosing connectivity with other boxes in the network. Problem is completely
aleatory and can affect any box. However rest of boxes are completely
reachables from FreeBSD while specific server is affected. Deleting ARP
entry in FreeBSD box solves the problem as you can see from the following
lines. Problem is showing quite frequently during the day.  Any hint about
this issue?

Thank you,
Best regards,
Luca Da Col

[root at srv001 /Scripts]#
[root at srv001 /Scripts]# ping SWI002-DMZ
PING SWI002-DMZ (10.192.149.45): 56 data bytes
^C
--- SWI002-DMZ ping statistics ---
20 packets transmitted, 0 packets received, 100% packet loss
[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]# arp -a
? (10.192.149.9) at 08:00:20:f2:cf:da on dc0 [ethernet]
? (10.192.149.33) at 00:07:ec:50:e4:08 on dc0 [ethernet]
? (10.192.149.44) at 00:0a:b7:8d:0b:00 on dc0 [ethernet]
? (10.192.149.45) at 00:07:85:a5:20:40 on dc0 [ethernet]
[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]# arp -d 10.192.149.45
10.192.149.45 (10.192.149.45) deleted
[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]# ping SWI002-DMZ
PING SWI002-DMZ (10.192.149.45): 56 data bytes
64 bytes from 10.192.149.45: icmp_seq=0 ttl=255 time=1.261 ms
64 bytes from 10.192.149.45: icmp_seq=1 ttl=255 time=1.196 ms
64 bytes from 10.192.149.45: icmp_seq=2 ttl=255 time=1.092 ms
64 bytes from 10.192.149.45: icmp_seq=3 ttl=255 time=1.093 ms
^C
--- SWI002-DMZ ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.092/1.160/1.261/0.072 ms


[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]#
[root at srv001 /Scripts]# arp -a
? (10.192.149.9) at 08:00:20:f2:cf:da on dc0 [ethernet]
? (10.192.149.33) at 00:07:ec:50:e4:08 on dc0 [ethernet]
? (10.192.149.44) at 00:0a:b7:8d:0b:00 on dc0 [ethernet]
? (10.192.149.45) at 00:07:85:a5:20:40 on dc0 [ethernet]