ar interface issues

[Jacques Fourie]

Hi,

I'm using a Digi SYNC/570i-PCI 2 port adapter on a system running FreeBSD
4.9-RELEASE as one end of a point-to-point link. If I change between ports
on the adapter, I need to reboot the FreeBSD box to get everything working.
Here is the sequence of events that leads to this scenario :

1.) ifconfig ar0 10.0.0.1 10.0.0.2 netmask 255.255.255.252 link2
2.) ping 10.0.0.2 - OK
3.) ifconfig ar0 down
4.) ifconfig ar0 delete
5.) swap cable to ar1
6.) ifconfig ar1 10.0.0.1 10.0.0.2 netmask 255.255.255.252 link2
7.) ping 10.0.0.2 - not OK, reboot required.

I've also noticed a lot of 
'ar1: transmit failed, ST0 0, ST1 50, ST3 f, DSR3 3.' after step 6 above.
After a reboot ar1 is working but the same happens when I try to switch to
ar0. I have also verified that the same condition occurs when using
netgraph. Any ideas on how I can go about trying to fix this would be
greatly appreciated.

regards,
jacques