5510 vlan reset?
Walter Roberson
if anyone else has encountered.
We start with a port in a port-based vlan that we created,
with appropriate PVID set. The port is *only* in that VLAN and
*not* in the default VLAN (VLAN 1).
The NIC that we have connected to the port is theoretically a gig
NIC but the NIC is not able to negotiate gig with the switch --
as if carrier simply is not detected. It is plausible that this
no-gig behaviour is the fault of the NIC. (We tried a brand new
Cat6 cable, and we tried a few different ports on the 5510
including some distant from each other.) Lack of gig is a nuisance
but not the problem I am leading up to.
When we force the NIC to 10/100 autonegotiate or (especially) if we
force the NIC to 100/FULL, the link does come up -- but
the 5510 drops the one port out of the port-based VLAN and puts it
back into VLAN 1!! If we then change the VLAN back on the 5510 then
we get regular communications.
We checked to be sure, and we do *not* have any kind of channel
bonding configured on the 5510 (i.e., the 5510 would have no reason
to decide that a new channel just came up in a channel group
and needs to have its VLAN reset to match the rest of the group).
The 5510 also does not have VTP (or the standard-based equivilent)
and the NIC wouldn't be emitting VTP frames anyhow.
This behaviour of resetting the VLAN for the port does not appear
to depend upon whether we have the 5510 port configured for autonegotiate
or for 100/FULL. Getting a proper link appeared to be more sure
when we forced the 5510 port to 100/FULL, so that is how we have it
at the moment.
We do seem to have noticed other issues with VLANs on this
particular 5510, dating back to the day of a power problem
(I don't recall at the moment whether the 5510 is not on a UPS
or if it was the UPS that itself went down.) When the 5510 came up
after that power problem, it had lost all of its VLAN information
(that is, the VLANs still existed but everything was only a
member of VLAN 1.)
Yesterday when we were testing the setting combinations, one of
the times that I forced the NIC parameters, the 5510 rebooted itself --
and when it came up, it had set everything to VLAN 1 again.
Thus, there is reason to suspect that the 5510 itself might not be
operating on all cylinders.
It is plausible that the reason we do not manage to negotiate gig with
this particular NIC might be the switch rather than the NIC -- but
failure to reach gig is not a major problem compared to losing all
layer 3 communications because the 5510 suddenly decided to
change the VLAN on the port. Now we will have to be concerned --
e.g., will rebooting the machine containing the NIC result in the
5510 resetting the VLAN?
Has anyone experienced a similar VLAN resetting issue? And managed
to get it resolved or worked-around?