[nsp] VLAN database propagation

[sthaug at nethelp.no]

> now that you have really scared me... how do I get rid of VTP?
> 
> I have 3 switches in 'master' mode. Would it be safe to change them to
> 'transparent'?

Changing them to transparent keeps the existing VLAN database, no problem
here. One possible problem:

- VTP transparent mode means that VTP pruning no longer works. If *one*
end of a link uses VTP (and VTP pruning) while the other does not, we
have seen links shut down (all VLANs pruned). The way to fix this is to
use "switchport trunk pruning vlan none" on the VTP speaking side.

You probably also want to use "switchport trunk allowed vlan ..." on all
relevant ports.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no