Cisco CCNP / BCMSN Exam Tutorial: Configuring PortFast And BPDU Guard - 0 views

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  #1 Olsson Doherty on 29 Sep 13

   

  In your CCNA reports, you learned all about PortFast and the problem it could cause if designed on the incorrect slot! Suitable only for move ports connected directly to just one host, PortFast allows a port working STP to go directly from blocking to forwarding mode. If you have an opinion about marketing, you will maybe claim to learn about turbo balancing south africa.
  
  A Cisco router gives a warning to you when you change PortFast:
  
  SW1( config )#int rapidly 0/5
  
  SW1( config-if )#spanning-tree portfast
  
  %Warning: portfast should only be permitted on ports attached to a
  
  single host. Connecting sites, concentrators, turns, bridges, etc.. Browsing To turbo reconditioning port elizabeth maybe provides aids you can tell your sister.
  
  For this screen when portfast is permitted, could cause temporary
  
  bridging loops. Use with CAUTION
  
  %Portfast has been constructed on FastEthernet0/5 but will simply
  
  have effect once the software is in a non-trunking function.
  
  SW1( config-if )#
  
  Not just will the move warn you in regards to the correct use of PortFast, but you must put the port into entry mode before PortFast will take effect. To get another perspective, we recommend people check-out: clicky.
  
  Now, you had believe will be enough of a warning, right? But there's a chance - only a - that someone is going to control to link a switch to a port working Portfast. That may lead to two main dilemmas, the very first being the formation of a switching loop. Remember, the reason we've listening and learning processes is to help alleviate problems with changing loops. The following issue is that there could be considered a new origin connection chosen - and it could be described as a change that's not even in your network!
  
  BPDU Guard protects against this disastrous possibility. The port will be turn off and placed in to error incapable state, found on the change as err-disabled, if any BPDU comes in on a port that's working BPDU Guard. A port put in err-disabled state should be reopened manually.
  
  BPDU Guard is off on all ports automatically, and is allowed as shown here:
  
  SW1( config )#int fast 0/5
  
  SW1( config-if )#spanning-tree bpduguard permit
  
  It is recommended allow BPDU Guard on any port you're working PortFast on. There is no cost in overhead, and it does avoid the possibility of a switch giving BPDUs into a port configured with PortFast - not to mention the possibility of a not under your control becoming a root switch to your network!.Turbo Clinic
  69 2nd Avenue
  Newton Park
  Port Elizabeth 6055‎ South Africa
  041 363 1177

   

  <div class="cArrow"> </div><div class="cContentInner">In your CCNA reports, you learned all about PortFast and the problem it could cause if designed on the incorrect slot! Suitable only for move ports connected directly to just one host, PortFast allows a port working STP to go directly from blocking to forwarding mode. If you have an opinion about marketing, you will maybe claim to learn about <a href="http://www.turboclinic.co.za/services/turbo-balancing" rel="nofollow">turbo balancing south africa</a>. <br /> <br /> A Cisco router gives a warning to you when you change PortFast: <br /> <br /> SW1( config )#int rapidly 0/5 <br /> <br /> SW1( config-if )#spanning-tree portfast <br /> <br /> %Warning: portfast should only be permitted on ports attached to a <br /> <br /> single host. Connecting sites, concentrators, turns, bridges, etc.. Browsing To <a href="http://www.turboclinic.co.za/services/turbo-reconditioning" rel="nofollow">turbo reconditioning port elizabeth</a> maybe provides aids you can tell your sister. <br /> <br /> For this screen when portfast is permitted, could cause temporary <br /> <br /> bridging loops. Use with CAUTION <br /> <br /> %Portfast has been constructed on FastEthernet0/5 but will simply <br /> <br /> have effect once the software is in a non-trunking function. <br /> <br /> SW1( config-if )# <br /> <br /> Not just will the move warn you in regards to the correct use of PortFast, but you must put the port into entry mode before PortFast will take effect. To get another perspective, we recommend people check-out: <a href="http://www.turboclinic.co.za/services/turbo-reconditioning" rel="nofollow">clicky</a>. <br /> <br /> Now, you had believe will be enough of a warning, right? But there's a chance - only a - that someone is going to control to link a switch to a port working Portfast. That may lead to two main dilemmas, the very first being the formation of a switching loop. Remember, the reason we've listening and learning processes is to help alleviate problems with changing loops. The following issue is that there could be considered a new origin connection chosen - and it could be described as a change that's not even in your network! <br /> <br /> BPDU Guard protects against this disastrous possibility. The port will be turn off and placed in to error incapable state, found on the change as err-disabled, if any BPDU comes in on a port that's working BPDU Guard. A port put in err-disabled state should be reopened manually. <br /> <br /> BPDU Guard is off on all ports automatically, and is allowed as shown here: <br /> <br /> SW1( config )#int fast 0/5 <br /> <br /> SW1( config-if )#spanning-tree bpduguard permit <br /> <br /> It is recommended allow BPDU Guard on any port you're working PortFast on. There is no cost in overhead, and it does avoid the possibility of a switch giving BPDUs into a port configured with PortFast - not to mention the possibility of a not under your control becoming a root switch to your network!.Turbo Clinic <br /> 69 2nd Avenue <br /> Newton Park <br /> Port Elizabeth 6055‎ South Africa <br /> 041 363 1177</div>

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