March 14th 09, 03:15 PM
Hello,
We have a very strange problem/behaivior that I cannot figure out.
We are running XP Embedded on a Motherboard with two ethernet NICs.
The first NIC is connected to a normal LAN.
The second NIC is connected to a small networked I/O-controller
mounted in the same box as the Motherboard.
The two NICs are bridged and given a DHCP address.
This connection gives the I/O-controller access to the LAN, and the
LAN access to
the I/O-controller. (Very neat mechanical solution/installation since
we dont need to use a HUB)
This works very well on most installations but .....
.... some customers have network switches that does not allow/like the
BPDU packets that the spanning tree algorithm uses.
These packets can be disabled by setting the DisableSTA flag in the
registry, but then unfortunally a very starnge behavior araises.
After rebooting the Motherboard the bridge will fail to get a DHCP
address and fallback to an automatic 169.254.nn.nn address.
It is possible to access the I/O-controller so the bridge is at least
forwarding the ethernet frames correctly.
The only way to get the "tcp/ip-stack"?? to up and running is to
unplug both network cables at the same time
and then reinserting them again. Unpluging and reinserting one at the
time will not work (both NICs must not have link).
I have tested and verified this behaivior with
- three different manufacturers motherboards,
- XP Pro and XP Embedded
- DHCP and static ip for the bridge
Does anyone have a solution for this problem.
Regards
/Peter/
We have a very strange problem/behaivior that I cannot figure out.
We are running XP Embedded on a Motherboard with two ethernet NICs.
The first NIC is connected to a normal LAN.
The second NIC is connected to a small networked I/O-controller
mounted in the same box as the Motherboard.
The two NICs are bridged and given a DHCP address.
This connection gives the I/O-controller access to the LAN, and the
LAN access to
the I/O-controller. (Very neat mechanical solution/installation since
we dont need to use a HUB)
This works very well on most installations but .....
.... some customers have network switches that does not allow/like the
BPDU packets that the spanning tree algorithm uses.
These packets can be disabled by setting the DisableSTA flag in the
registry, but then unfortunally a very starnge behavior araises.
After rebooting the Motherboard the bridge will fail to get a DHCP
address and fallback to an automatic 169.254.nn.nn address.
It is possible to access the I/O-controller so the bridge is at least
forwarding the ethernet frames correctly.
The only way to get the "tcp/ip-stack"?? to up and running is to
unplug both network cables at the same time
and then reinserting them again. Unpluging and reinserting one at the
time will not work (both NICs must not have link).
I have tested and verified this behaivior with
- three different manufacturers motherboards,
- XP Pro and XP Embedded
- DHCP and static ip for the bridge
Does anyone have a solution for this problem.
Regards
/Peter/