RSTP 801.1w

Does anyone know if Rapid Spanning tree will be on the CCNA exam? Has anyone seen any questions regarding RSTP?

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It's more of a CCNP topic -- but you should know a few of the basics.

The single most important thing you might want to know is -- 802.1w

No editing the 801.1w in your subject line to make me look silly -- but I suspect that was just a typo.

jrambar

whoops! Sorry, I have been reading all night, 802.1w is correct. and STP is 802.1D...HAAAA...I'm getting it now! My brain is fried, maybe I should crawl into bed with wifey and snap back into reality, hopefully I won't be talking CCNA in my sleep, almost did last night...scary...

mikej412

jrambar wrote:

hopefully I won't be talking CCNA in my sleep, almost did last night...scary...

shouldn't be scary if you're passing it....

pleasant dreams

David_HX

Have you ever used this commands ?
SWITCH-A #interface fastethernet 0/x
SWITCH-A (config-if) #spanning-tree portfast

............ and verify by executing

SWITCH-A #show spanning-tree interface fastethernet 0/x

Just use it on "edge network" switch ports where there will be no chance of a bridging loop.

DvD

mikej412

David_HX wrote:

Have you ever used this commands ?
SWITCH-A #interface fastethernet 0/x
SWITCH-A (config-if) #spanning-tree portfast

Yeah..... but us CCNPs are trained professionals. CCNAs can only try this at home.

50 seconds to reconverge the network after a switch link failure is just plain awful - that's what you get with common ordinary plain STP. Luckly, when you're old enough and experienced enough (BCMSN) you know additional stuff about switching and can get that down to a second or two.

David_HX

Isn't 'portfast' supposed to bypass the Listening and Learning stages of the convergence process and take the port directly from Blocking to Forwarding ? Thats the way I understand the process,, am I missing something here ?

DvD

mikej412

David_HX wrote:

Isn't 'portfast' supposed to bypass the Listening and Learning stages of the convergence process and take the port directly from Blocking to Forwarding ? Thats the way I understand the process,, am I missing something here ?

DvD

Right -- its for access ports only. No listening, no learning. Since its a user port, there is no chance for a loop anyways and there never were any convergence issues....

... until some idiot does plug a switch into the port -- then if a BPDU is received, Port Fast is abandoned, the port placed in blocking, and the switch runs through the entire Spanning Tree procedure.

That's why CCNAs only get to try this at home.... unless the CCNA is covering portfast now? Maybe I'm out of date....

duncnz

mikej412 wrote:

David_HX wrote:

Isn't 'portfast' supposed to bypass the Listening and Learning stages of the convergence process and take the port directly from Blocking to Forwarding ? Thats the way I understand the process,, am I missing something here ?

DvD

Right -- its for access ports only. No listening, no learning. Since its a user port, there is no chance for a loop anyways and there never were any convergence issues....

... until some idiot does plug a switch into the port -- then if a BPDU is received, Port Fast is abandoned, the port placed in blocking, and the switch runs through the entire Spanning Tree procedure.

That's why CCNAs only get to try this at home.... unless the CCNA is covering portfast now? Maybe I'm out of date....

The CCNA material I have, covers portfast to the extent you mentined above...

"its for access ports only. No listening, no learning. Since its a user port, there is no chance for a loop anyways " ...adding, exercise with caution!