It seems that FreeBSD-7.0 does not use the available MTU

[Eitan Shefi]

Hi,
 
I am using 2 hosts with FreeBSD-7.0 connected directly.
When I change the MTU to a value greater then 1500, for example 3000,
and then send "ping" with message size 2500, from one host to the other,
the other host gets more then one ICMP packet, even thaw the message
that was send is match smaller then the MTU.
 
I tried to run this test using a different NIC, but I got the same
behavior.
 
I run:
1.  On both hosts:
     ifconfig mtnic0 mtu 3000
2.  Than on one host I run:
     tcpdump -i mtnic0 icmp
3.  And on the other host I run:
    ping -s 2500 -c 1 OTHER_HOST_IP   (ping to "mtnic0" on the other
host)
 
On the receiving side I get the output:
 
[root at sw260 ~]# tcpdump -i mtnic0 icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol
decode
listening on mtnic0, link-type EN10MB (Ethernet), capture size 96 bytes
13:12:45.904454 IP 11.4.12.5 > 11.4.12.6: ICMP echo request, id 22550,
seq 0, length 1480
13:12:45.904463 IP 11.4.12.5 > 11.4.12.6: icmp
13:12:45.904477 IP 11.4.12.6 > 11.4.12.5: ICMP echo reply, id 22550, seq
0, length 1480
13:12:45.904480 IP 11.4.12.6 > 11.4.12.5: icmp
 
 I will be happy to get any advice on how to resolve this issue. .
 
 
Thanks,
 
Eitan Shefi