arplookup problems

[Daemon]

I hope this is the correct list to post to, if not, I apologize.  I've
had an ongoing problem with arplookup for some months now and as of yet,
haven't been able to find anything on the web concerning my particular
problem.  Every 24 hours, almost to the minute, I get the following errors;

*Note This proceeds each arplookup failure
em0: Link is Down
em0: Link is up 100 Mbps Full Duplex

Sep 25 01:32:49 thisbox kernel: arplookup 169.0.0.1 failed: host is not
on local network
Sep 25 01:33:05 thisbox kernel: arplookup 10.32.240.171 failed: host is
not on local network
Sep 26 01:23:37 thisbox kernel: arplookup 169.0.0.1 failed: host is not
on local network
Sep 26 01:23:49 thisbox kernel: arplookup 10.32.240.171 failed: host is
not on local network
Sep 27 01:23:35 thisbox kernel: arplookup 169.0.0.1 failed: host is not
on local network
Sep 27 01:23:48 thisbox kernel: arplookup 10.32.240.171 failed: host is
not on local network

When this happens, one by one, each of my (ssh, gaim, irc, etc.)
connections time out until every connection is dead.  I'm using
RoadRunner Business Class with a static IP on em0 and an internal subnet
172.16.XXX.XXX on em1.  I was getting the errors on two older nics I
had, so I bought new nics in hopes that would correct the problem.  I
was running FreeBSD 5.4-Release p7 and switched to FreeBSD 5.4-STABLE
about a week ago.  I'm running the most current DHCP server, IPFW2, and
NATD.

I have the following in /etc/sysctl.conf
kern.polling.enable=1
net.inet.tcp.syncookies=0
net.inet.udp.blackhole=1
net.inet.tcp.blackhole=2
# TCP send and receive spaces
net.inet.tcp.sendspace=1048576
net.inet.tcp.recvspace=1048576
# Socket queue defense against SYN attacks
kern.ipc.somaxconn=1024
# Redirects
net.inet.icmp.drop_redirect=1
net.inet.icmp.log_redirect=1
net.inet.ip.redirect=0
# Subnet
net.link.ether.bridge_cfg=em0,em1
net.link.ether.bridge.enable=0
net.link.ether.bridge.ipfw=0
net.link.ether.ipfw=1
# ARP cleanup
net.link.ether.inet.max_age=1200
# Source routing
net.inet.ip.sourceroute=0
net.inet.ip.accept_sourceroute=0
# Broadcast ECHO response
net.inet.icmp.bmcastecho=0
# Other broadcast probes
net.inet.icmp.maskrepl=0
net.inet.ip.fw.dyn_ack_lifetime=3600
net.inet.ip.fw.dyn_buckets=1024
net.inet.ip.fw.one_pass=0

I have the following in my kernel conf;
# Firewall Stuff
options         IPFIREWALL_DEFAULT_TO_ACCEPT
options         IPFIREWALL
options         IPFIREWALL_FORWARD
options         IPFIREWALL_FORWARD_EXTENDED
options         IPFIREWALL_VERBOSE
options         IPFIREWALL_VERBOSE_LIMIT=10
options         IPDIVERT
options         DUMMYNET
options         BRIDGE
options         IPSTEALTH
options         HZ=1000
options         DEVICE_POLLING

It is probably a bad idea to post my /etc/rc.conf ifconfig info here,
but since I'm almost positive that in order for someone to help me track
this down, they're going to want/need to know what is in there, I'll
wait in hopes of a response first.


Regards,

Mark