Bridging Packet Loss

[Tim Wilde]

I'm experiencing 2-3% packet loss in a bridging configuration on a FreeBSD
4.8-p13 box, Intel Celeron 700MHz with 256MB RAM, dual fxp NICs (it's a
Dell Poweredge 350).  I'm running ipfw2 rules on the bridge, but have
ruled them out as the cause of the loss by clearing them out - the loss
still occurs.  We're seeing around 5Mbps of traffic bidirectionally across
the server.  We were running this exact same packet load, with the same
server and the same firewall rules, as a router, without this loss.  The
packet loss is observed pinging the IP on the firewall from the inside
network, as well as pinging across the bridge.  Output from ifconfig and
relevant sysctls is below.  Anyone have any suggestions as to what might
be causing this or how we could rectify it?  Both ends of both connections
are locked down to 100Mbps full-duplex (server and switches).  Thanks!

fxp0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::202:b3ff:fe86:8afc%fxp0 prefixlen 64 scopeid 0x1
        ether 00:02:b3:86:8a:fc
        media: Ethernet 100baseTX <full-duplex>
        status: active
fxp1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::202:b3ff:fe86:8afd%fxp1 prefixlen 64 scopeid 0x2
        inet 63.208.196.57 netmask 0xffffff80 broadcast 63.208.196.127
        ether 00:02:b3:86:8a:fd
        media: Ethernet 100baseTX <full-duplex>
        status: active

net.link.ether.inet.prune_intvl: 300
net.link.ether.inet.max_age: 1200
net.link.ether.inet.host_down_time: 20
net.link.ether.inet.maxtries: 5
net.link.ether.inet.useloopback: 1
net.link.ether.inet.proxyall: 0
net.link.ether.inet.log_arp_wrong_iface: 1
net.link.ether.bridge_cfg: fxp0,fxp1
net.link.ether.bridge: 1
net.link.ether.bridge_ipfw: 1
net.link.ether.bridge_ipf: 0
net.link.ether.bridge_ipfw_drop: 0
net.link.ether.bridge_ipfw_collisions: 0
net.link.ether.verbose: 0
net.link.ether.bdg_split_pkts: 0
net.link.ether.bdg_thru: 352262925
net.link.ether.bdg_copied: 0
net.link.ether.bdg_copy: 0
net.link.ether.bdg_predict: 481965741
net.link.ether.bdg_fw_avg: 0
net.link.ether.bdg_fw_ticks: 0
net.link.ether.bdg_fw_count: 0
net.link.ether.ipfw: 0

If anyone needs anything else to diagnose, let me know.  Thanks.

Tim Wilde

-- 
Tim Wilde
twilde at dyndns.org
Systems Administrator
Dynamic DNS Network Services
http://www.dyndns.org/