CCNP SWITCH/Implementing Spanning Tree - Revision history

Rael: /* Summary */

2014-02-04T23:09:41Z

‎Summary

2014-02-04T23:07:55Z

‎Comparison Between Aggressive Mode UDLD and Loop Guard

2014-02-04T22:59:52Z

‎Loop Guard

2014-02-04T22:58:05Z

‎Root Guard

2014-02-04T22:56:10Z

‎BPDU Guard

2014-02-04T22:55:18Z

‎BPDU Guard

2014-01-31T13:20:43Z

‎Loop Guard

2013-08-13T06:12:22Z

‎Basic PVRST+ configuration

2013-01-25T07:38:55Z

2012-02-29T13:18:47Z

‎RSTP

@@ Line 243: / Line 243: @@
 =Summary=
 {{Source cli}}
 [[Category:Cisco]][[Category:CCNP]]
 [[Category:Spanning Tree]]

@@ Line 205: / Line 205: @@
 </source>
 ==Comparison Between Aggressive Mode UDLD and Loop Guard==
 {| class="wikitable sortable" style="text-align:center" border=1
 |+ UDLD and Loop Guard Comparison
@@ Line 218: / Line 219: @@
 The most noticeable difference between aggressive mode UDLD and Loop Guard is with regard to STP. UDLD cannot detect failures caused by problems in software in the designated switch not sending the BPDU.<br/>
 Nevertheless, aggressive mode UDLD is more robust in its capability to detect unidirectional links on EtherChannel. Loop Guard blocks all interfaces of the EtherChannel in such a failure by putting the EtherChannel into the loop-inconsistent state for a VLAN or for all VLANs, whereas aggressive modeUDLD disables the single port exhibiting problems.
 ==Flex Links==
 Flex Links are configured on one Layer 2 interface (the active link) by assigning another Layer 2 interface as the Flex Links or backup link. The Flex Links can be on the same switch or on another switch in the stack. When one of the links is up and forwarding traffic, the other link is in standby mode.

@@ Line 175: / Line 175: @@
 </source>
 ==Loop Guard==
-Loop Guard provides additional protection against Layer 2 forwarding loops (STP loops). A bridging loop happens when an STP blocking port in a redundant topology erroneously transitions to the forwarding state. This usually occurs because one of the ports of a physically redundant topology (not necessarily the STP blocking port) has stopped receiving STP BPDUs. In STP, switches rely on continuous reception or transmission of BPDUs, depending on the port role. (A designated port transmits BPDUs, whereas a non-designated port receives BPDUs.)
+Loop Guard provides additional protection against Layer 2 forwarding loops (STP loops). A bridging loop happens when an STP blocking port in a redundant topology erroneously transitions to the forwarding state. This usually occurs because one of the ports of a physically redundant topology (not necessarily the STP blocking port) has stopped receiving STP BPDUs. In STP, switches rely on continuous reception or transmission of BPDUs, depending on the port role. (A designated port transmits BPDUs, whereas a non-designated port receives BPDUs.)<br/><br/>
 <source lang=cli>
 switch(config)# ! Global configuration command.

@@ Line 159: / Line 159: @@
 </source>
 ==Root Guard==
 <source lang=cli>
 switch(config-if)# ! interface configuration command.
 switch(config-if)# <input>spanning-tree guard root</input>
 </source>
 ==Portfast==
 Spanning Tree Portfast enables edge port status on an interface and makes the port go from disabled to forwarding immediately. PortFast can prevent DHCP timeouts

@@ Line 143: / Line 143: @@
 *'''Flex Links''': Flex Links is a Layer 2 availability feature that provides an alternative solution to STP and allows users to turn off STP and still provide basic link redundancy
 ==BPDU Guard==
-BPDU Guard or RootGuard is configured on ports from the access switch to the end device, as is PostFast<ref>Designing Cisco Network Services Architectures p. 39</ref>
+'''Best Practise:''' BPDU Guard or RootGuard is configured on ports from the access switch to the end device, as is PostFast<ref>Designing Cisco Network Services Architectures p. 39</ref>
 <source lang=cli>
 switch(config)# ! Global configuration command. Configures BPDUGuard on alle PortFast ports

@@ Line 115: / Line 115: @@
 To be a part of the same region all switches need to share the same attriubutes throughout the region.
 =Configuring Spanning Tree=
-==Basic PVRST+ configuration==
+==Basic RPVST+ configuration==
 <source lang=cli>
 switch(config)#<input> spanning-tree mode rapid-pvst</input>
@@ Line 121: / Line 121: @@
 switch(config)# <input>spanning-tree vlan 3 root secondary</input>
 </source>
 ==Basic MST configuration==
 <source lang=cli>

← Older revision		Revision as of 07:38, 25 January 2013
Line 236:		Line 236:
	{{Source cli}}		{{Source cli}}
	[[Category:Cisco]][[Category:CCNP]]		[[Category:Cisco]][[Category:CCNP]]
		+	[[Category:Spanning Tree]]

@@ Line 230: / Line 230: @@
 |[[Image:ScreenShot1098.jpg|800px|left|thumb|RSTP Proposal]]
 |}
-When a designated port is in a discarding or learning state (and only in this case), it sets the proposal bit on the BPDUs it sends out. This is what occurs for port p0 of the root bridge, as shown in Step 1 of Figure. Because Switch A receives superior information, it immediately knows that p1 is the new root port. Switch A then starts a sync process that puts nonedge designated ports in blocking state as it needs to verify that all its ports are in-sync with the new superior BPDU received.
+When a designated port is in a discarding or learning state (and only in this case), it sets the proposal bit on the BPDUs it sends out. This is what occurs for port p0 of the root bridge, as shown in Step 1 of Figure. Because Switch A receives superior information, it immediately knows that p1 is the new root port. Switch A then starts a sync process that puts nonedge designated ports in blocking state as it needs to verify that all its ports are in-sync with the new superior BPDU received.<br/><br/>
 =Summary=
 {{Source cli}}
 [[Category:Cisco]][[Category:CCNP]]