CCNP Switch : Advice for using MST?

Node Man

Hi Everyone,
I am studying for CCNP Switch. I can initially set up MST just fine. At least good enough for the exam. However, my lab has grown to almost a production environment, it has 7 switches, including 1 as a management switch.

My problem is once I get MST installed and stable, I bump offline all switches when I make an Instance change. So my question is: How do I avoid dropping switches when I make MST changes?

Thanks!

theodoxa

VTPv3

It's not on the current SWITCH exam (it is on the new 300 series exam) as far as I know, but VTPv3 can carry VLANs, Private VLANs, and MST Instances. It's really cool. In my lab, I configured VTPv3 on all 4 switches, then created a couple of MST Instances on the "VTPv3 Primary Server" and almost immediately, the instances were on all 4 switches.

RouteMyPacket

I wouldn't worry too much about MST, you won't run into it in Enterprise environments most likely. I only know of one Enterprise that is using it and that is because the Engineer came from a Service Provider and simply knows no different, I would hate to be the Engineer coming in behind him once he is gone.

Node Man

Thanks Guys, so VTPv3 is the solution? Frankly I am getting tired of crashing my lab when I make an instance change. I look forward to getting back to a more humane STP.

RouteMyPacket

Node Man wrote: »

Thanks Guys, so VTPv3 is the solution? Frankly I am getting tired of crashing my lab when I make an instance change. I look forward to getting back to a more humane STP.

Again, focus on what is needed to pass the exam, there is no mention of MST int he objectives. It's too easy to burn time going down these rabbit holes trust me I know.

Danielh22185

I always thought the concept of MST was a bit funny. Seems almost like a bandaid type solution to conserve switch resources for older switches, years and years ago I am sure it held more validity but not now. It defeintly is not a popular concept in the real world as RMP mentioned.

theodoxa

Danielh22185 wrote: »

I always thought the concept of MST was a bit funny. Seems almost like a bandaid type solution to conserve switch resources for older switches, years and years ago I am sure it held more validity but not now. It defeintly is not a popular concept in the real world as RMP mentioned.

I like MST. I know switches are fast enough to handle PVST just fine, but...Imagine you have 20 VLANs, but let's say only 2 possible root bridges (the distribution switches for the switch block). You could run PVST, but that would give you 20 STP instances. Not only does that consume more resources, but show commands without specifying a specific VLAN would give pages upon pages of output. OTOH, you could configure 2 MST instances (one for 10 of the VLANs and one for the other 10 VLANs), which would use less resources and make your show commands generate a lot less output.

theodoxa

RouteMyPacket wrote: »

Again, focus on what is needed to pass the exam, there is no mention of MST int he objectives. It's too easy to burn time going down these rabbit holes trust me I know.

642-813

1.5 Configure loop prevention for the VLAN based solution

That's a pretty open-ended topic that could cover any flavor of STP (CST, PVST, RPVST, or MST)

300-115

1.6.a PVST+, RPVST+, MST

Danielh22185

theodoxa wrote: »

642-813



That's a pretty open-ended topic that could cover any flavor of STP (CST, PVST, RPVST, or MST)

300-115

Yes I like the more defined topics for the new test. I am actually kid of excited to take the new one.

gorebrush

Yeah, I like MST first. Despite newer switches running many instances of STP - it's just good management to get them under a single process.