Hello,I was just checking on this posting and noticed it still shows "not answered".  Everything I mentioned should address your original questions but if not please feel free to send an update and I'm sure we can get any other details figured out.  ...

Generally speaking there are security concerns with using native vlans and since everyone knows that the default native vlan id is 1 it's always a good idea to change it.Regards.

To clarify a few other points;1. difference between default vlan and native vlanDefault VLAN only applies to ACCESS ports...The reason is because for a switch to work in a plug & play fashion the ports must all belong to the same vlan as part of the ...

So the exact answer to the question is that the native vlan of a trunk link does allow untagged traffic to traverse the link.In other words a trunk link (by default) will not drop untagged traffic.  When this untagged traffic arrives on the other end...

If each closet switch is connected to each "core switch" this issue  shouldn't require any special configurations or protocol outside of  OSPF.  What is trying to be accomplished here is fundamental...how and where summarization is being configured s...