[c-nsp] How to improve C3750G switch uplink speed?

[Jonathan Brashear]

>  enabling bpduguard will prevent any device that participate in 
> the spanning tree to talk to the network, reducing the risk of having ports 
> in the wild where users *might* create a network loop.  ___Just make sure you 
> enable an automatic recovery for the port (errdisable recovery) or else this 
> may require you to manually intervene to restore connectivity.___

Sage advice, especially in a data center environment.  Bpduguard has its uses, but only if you can automate the recovery.  Otherwise it becomes a massive time-sink.

As an aside, PVST can become an issue when you're scaling up into dozens/hundreds of VLANs.  All of those spanning tree instances can start to become a drag on your network's cpu/memory resources.  You might also consider moving to MSTP if you're using hundreds of VLANs & PVST to free up a bit of your router/switch performance.

Network Engineer, JNCIS-M
> 214-981-1954 (office) 
> 214-642-4075 (cell)
> jbrashear at hq.speakeasy.net 
http://www.speakeasy.net
-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Tristan Gulyas
Sent: Friday, May 22, 2009 6:35 AM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] How to improve C3750G switch uplink speed?

Hi,

I find that using

spanning-tree uplinkfast

is best-suited for uplink ports.

If all your equipment supports it, I strongly suggest using Rapid Per-VLAN 
spanning tree:

spanning-tree mode rapid-pvst

Which will reduce your convergence time dramatically.

I've found standarizing on portfast for PC/server connections is always a 
good idea - enabling bpduguard will prevent any device that participate in 
the spanning tree to talk to the network, reducing the risk of having ports 
in the wild where users *might* create a network loop.  Just make sure you 
enable an automatic recovery for the port (errdisable recovery) or else this 
may require you to manually intervene to restore connectivity.

Good luck,
Tristan


----- Original Message ----- 
From: <masood at nexlinx.net.pk>
To: "Darren Yang" <pigsign.pykota at gmail.com>
Cc: <cisco-nsp at puck.nether.net>
Sent: Tuesday, May 12, 2009 8:52 PM
Subject: Re: [c-nsp] How to improve C3750G switch uplink speed?


> You are using this port for UPLINK, and it could be a trunk port. I
> strongly suggest you should not use portfast on this port. This way you
> can avoid loops and 30 second wait will be worth it.
>
> Regards,
> Masood
> Blog: http://weblogs.com.pk/jahil/
>
>
>> Hi,
>>
>> When I plug wire into c3750g port, it would wait about "30sec" then
>> change to uplink status.
>>
>> Are there any method can cut down uplink time?
>>
>>
>> Regards,
>> Pigsign
>> _______________________________________________
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>
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