Why ue0 do ARP on non local address when using static route?

[Jin Guojun]

This is 8.3-Release on a HP EliteBook 8460p (4-core i5) with an on board Intel 
(em0) interface.
When attached a Trendent TU2-ET100 USB Ether dongle for a second interface, it 
has no problem to talk to the local network (10.234.37.0/24), but it has problem 
to talk to a remote network or host (10.227.148.0/24) via eu0 interface.
When a remote host ping this host or this host ping that remote host, ARP 
request is always showing up.
A static route is set and remote host is no part of the local sub net, why ARP 
is going on?

Is any sysctl parameter can fix this problem?

-Jin


Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            10.234.16.1        UGS         0  2841993    em0
10.227.148.52      10.234.37.80       UHS         0       26    ue0
10.234.16.0/22     link#1             U           0        0    em0
10.234.17.41       link#1             UHS         0        0    lo0
10.234.37.0/24     link#8             U           0        3    ue0
10.234.37.80       link#8             UHS         0        0    lo0
127.0.0.1          link#7             UH          0      492    lo0

ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=80008<VLAN_MTU,LINKSTATE>
        ether 00:50:b6:00:a4:91
        inet 10.234.37.80 netmask 0xffffff00 broadcast 10.234.37.255
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

ping from 10.227.148.52
12:16:37.924425 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 1, length 64
12:16:37.924442 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:38.931919 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 2, length 64
12:16:38.931937 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:39.931662 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 3, length 64
12:16:39.931680 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:40.931656 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 4, length 64
12:16:40.931674 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:41.931519 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 5, length 64
12:16:41.931533 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:42.931643 IP 10.227.148.52 > 10.234.37.80: ICMP echo request, id 21002, 
seq 6, length 64

ping to 10.227.148.52
12:16:42.931661 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:16:59.724724 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:17:00.725715 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:17:01.725883 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:17:02.726690 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
12:17:03.727677 ARP, Request who-has 10.227.148.52 tell 10.234.37.80, length 28
^C
45 packets captured
1557 packets received by filter