Anybody using these cards?

I've got a pair of machines connected with a crossover cable.

I can ping, including big packets, but I can't open a TCP connection 
over that link.  (Or at least ping worked at one point.  It doesn't 
work now.  ???)

I've also got fxp cards on both machines.  They work fine.
My kernel is compiled without IPv6.


From dmesg at startup:

  sip0 at pci1 dev 10 function 0: NatSemi DP83815 10/100 Ethernet
  sip0: interrupting at irq 11
  sip0: Ethernet address 41:8e:7b:37:98:a8
  ukphy0 at sip0 phy 0: Generic IEEE 802.3u media interface
  ukphy0: OUI 0x080017, model 0x0002, rev. 1
  ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto


From /var/log/messages:

  /netbsd: arp_rtrequest: bad gateway value


From ifconfig -a
fxp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        address: 00:50:8b:01:8e:af
        media: Ethernet autoselect (100baseTX full-duplex)
        status: active
        inet 16.4.80.43 netmask 0xffffff00 broadcast 16.4.80.255
sip0: flags=fbff<UP,BROADCAST,DEBUG,LOOPBACK,POINTOPOINT,NOTRAILERS,RUNNING,NOARP,PROMISC,ALLMULTI,SIMPLEX,LINK0,LINK1,LINK2,MULTICAST> mtu 1500
        address: 41:8e:7b:37:98:a8
        media: Ethernet autoselect (100baseTX full-duplex)
        status: active
        inet 10.0.20.43 -> 10.0.20.255 netmask 0xffffff00 broadcast 10.0.20.255

What does this arrow    ^ mean?