[nsp] vlans and VTP

[Stephen J. Wilcox]

On Wed, 28 May 2003 jlewis at lewis.org wrote:

> On Wed, 28 May 2003, Stephen J. Wilcox wrote:
> 
> > VTP is useful, save a lot of vlan config but as you say beware the config 
> > number, this isnt a problem if you config your switches carefully and use a 
> > domain and password.
> 
> So a password will keep an accidental switch (that happened to have the 
> same domain) from wiping things out, but what happens when the VTP server 
> goes down or dies and is replaced?

You can run more than one switch as server and the others as clients so you 
could have a primary and secondary (altho theyre equal technically)

Depends on your setup, if youve a reasonable size lan you may have a couple of
Cat6k which you want to be servers and are the 'core' and you might have lots of
Cat29xx scattered around as local access switches, in this case you dont want 
the hassle of configure 10 or 20 switches each time so config all the Cat29xx as 
client and do all your vlan changes on the Cat6ks

Course if you only have 3 switches and are happy to config vlans on each one 
(i'm too lazy myself!) and dont like vtp then disable it, no problem.

> > You must have the vlan configured on all switches for traffic to pass, I'm 
> > guessing you didnt initally hence the vlan wasnt allowed thro but when you 
> > changed the vtp settings the vlan was created.
> 
> Initially, 3550b was the VTP server, and 3550a was a VTP client...so I 
> expected defining vlan 101 on 3550b would be sufficient...but for some 
> reason it wasn't.

It should have worked but maybe there was some issue, vtp not setup right or the 
server config number was higher than the client... 

> > Not sure on your layout, depends on your needs altho sw1 and sw2 seem to
> > not be doing anything useful..
> 
> sw1 and sw2 are intended to connect the routers to a collection of 
> switch3's.  When/if traffic dictates, the router ethernet interfaces will 
> be upgraded to gigE and sw1 and 2 will be swapped out for gigE switches 
> with gigE connections to the collection of switch3's.

Ok so traditional core-access setup, makes sense.

I'd consider using a Cat6000 rather than router1/switch1 and r2/s2 tho, that way 
you can combine the functionality in one box, get better performance and the gig 
ports are nice and cheap. As before you know your network better tho of course 
:)

Steve