RSTP+ question

itdaddy

Hey guys,
on our switches at work 4 of them at a branch site, they are using pvst, but if there is spanning-tree portfast configured on each access port on the switches, I dont see why I need to bump up spanning-tree mode to rapid-pvst? do you?

instant000

Portfast only addresses ports that hosts plug into, as you already noted.

Rapid spanning tree addresses links to other bridges.

If this doesn't make sense, you can try this link:

Understanding Rapid Spanning Tree Protocol (802.1w)* [Spanning Tree Protocol] - Cisco Systems

itdaddy

so I could technially remove the Spanning-tree portfast on each access port and place switches in Spanning-tree mode rapid-pvst to replace it right? or should i just leave port fast and change it for faster uplink convergence? I guess dumb question (I read the link) but placing uuplinks in Dis/Li/fwd is the wise? or won't this cause loops? being so fast now. I mean you are not suppose to place portfast on the upinks, it is okay that uplinks have only 3 states? And this is for STP calculation speed increase? Sorry I am all over just trying to understand it..

MrBrian

You could bump them up to rapid spanning tree if you want. If you already have portfast configured, then it may speed convergence on your inter switch links.. What kind of redundancy is in place between the switches? I.e. unused links as backups or etherchannel bundles, etc

itdaddy

actually what the guy had before was crap...there is no full-mesh. There are switches and they are in a Z pattern Root core, Sw1, Sw2, DMZ.
I want to bump it up to spanning-tree mode rapid-pvst, and i guess could leave the portfast on each access port can't hurt. and I am going to wire it Full-mesh with etherchannels is that sound good? if i change it over do you forsee any isssues? I am going to do it on a saturday after hours haahah cause I now crap happens haha so do you see bud anything happening that I should be aware of? I want to enable Uplinkast and backbonefast as well. So in summary this is what i want to do to the existing topology is to enhance its convergence performance:
1. wire it in a full mesh toplogy
2. apply etherchannels to the upllinks
3. add uplinkast, backbonefasst
4. change spanning-tree mode to rapid-pvst
I think that should boost the perfromance does this souond good?
anything i should look for as any issues maybe?
thansk i am kind of excited i am studying CCNP Switch and I get to see this stuff 1st hand sweeet. thanks man for you help and guidance..

instant000

you worry about there only being three states, and actually, Perlmann once commented that she thought that three states should be enough, so take that for all its worth.

If you can, you want to probably localize vlans to the access layer as much as you can, so you can minimize the usage of spanning tree as much as possible.

EDIT: I must need sleep. rapid converges better than normal, LOL. whether or not you get loops has no bearing on the convergence time, actually. localizing the vlans can help it the most, though.

MrBrian

itdaddy wrote: »

actually what the guy had before was crap...there is no full-mesh. There are switches and they are in a Z pattern Root core, Sw1, Sw2, DMZ.
I want to bump it up to spanning-tree mode rapid-pvst, and i guess could leave the portfast on each access port can't hurt. and I am going to wire it Full-mesh with etherchannels is that sound good? if i change it over do you forsee any isssues? I am going to do it on a saturday after hours haahah cause I now crap happens haha so do you see bud anything happening that I should be aware of? I want to enable Uplinkast and backbonefast as well. So in summary this is what i want to do to the existing topology is to enhance its convergence performance:
1. wire it in a full mesh toplogy
2. apply etherchannels to the upllinks
3. add uplinkast, backbonefasst
4. change spanning-tree mode to rapid-pvst
I think that should boost the perfromance does this souond good?
anything i should look for as any issues maybe?
thansk i am kind of excited i am studying CCNP Switch and I get to see this stuff 1st hand sweeet. thanks man for you help and guidance..

1 and 2: Yes doing full-mesh with etherchannels is probably a good idea. That way if one of the links in the bundle goes down, you'll still have connectivity.

3: UplinkFast and BackboneFast aren't used with rapid-pvst because they are built in. Those are Cisco proprietary features used only if you're running regular 802.1d spanning tree. Rapid-pvst has these built in. You can configure rapid-pvst and try to configure them, but if you then do a "sho spanning-tree summary" you'll see it says "enabled but inactive in rapid-pvst mode." Just bump them up to rapid-pvst and you're good.

4: Yes sir

Here's a link I used to verify my thoughts. From the table of contents at the top, if you go to UplinkFast and BackboneFast, and start from there, you'll see what I mean. Hth

Spanning Tree from PVST+ to Rapid-PVST Migration Configuration Example - Cisco Systems

7of9

The only other thing I'd add is, do you have dual distribution switches for all these vlans? If so, I'd also make sure to rig the elections to share the load, if they are a decent number of them and echo the goal of minimizing the size of your spanning tree wherever possible.

Have fun!

Mrock4

itdaddy is alive!

itdaddy

Mrock4 hahhha yeah dude I have been so busy being a manager it sucks but to be honest..I am hammering out CCNP this year and I hope CCDP..and then on to maybe SP or VP and then NP-Wifi and then CCIE-written. I have decided I want to go the CCIE-r/s and then maybe CCIE-SP and the Security. I think I can do it...I am trying to get my lab built up and getting my Cisco learning method down and hammer time. Here is my home lab...yeah it is in my kitchen and getting married soon haha This year May or August to a girl from Cebu Philippines wow is she hot! and well have to move rack in garage..Going to use 2 AP/Bridge wifi units to bring them to my house and then connect through my ASA 5505 at home via vpn to my job so i can just vpn into to practicde at work hee heeh any lab scenarios. I have a ACP unit to power up any device on want remotely and a 2511 access router freaking love it... yep I am getting My Cisco on!.Golf..hahahahhh...so here goes everything...see my lab below..plus going to use GNS3 on some things...I do have 4 1841 with IOS 15.x on them....here she is love my Ohm rack ...super light and it is marked with measurement marks for even install of devices and cheap under 200.00 bucks..love it...

MrBrian

That's one awesome kitchen. What you cooking up in there other than protocols.. haha

ciscoman2012

Now that's just cruel giving us a picture that small.....

itdaddy

MrBrian haah I know yeah it looks funny but I am single for now but when wife arrives it goes in the garage and I will use a wifi bridge to get to it hahaa

itdaddy

funny how we try to get rid of STP hahaah i have been reading on L3 routing and getting rid of STP huh! funny but good concepts