{"id":79,"date":"2014-06-25T14:23:07","date_gmt":"2014-06-25T14:23:07","guid":{"rendered":"http:\/\/feralpacket.org\/?p=79"},"modified":"2015-01-03T11:17:26","modified_gmt":"2015-01-03T11:17:26","slug":"v5-written-and-lab-optional-spanning-tree-features-notes","status":"publish","type":"post","link":"https:\/\/feralpacket.org\/?p=79","title":{"rendered":"v5 Written and Lab: Optional Spanning-Tree Features Notes"},"content":{"rendered":"

v5 Written:
\n2.1.f Implement and troubleshoot spanning-tree
\n2.1.f [i] PVST+ \/ RPVST+ \/ MST
\n2.1.f [ii] Switch priority, port priority, path cost, STP timers
\n2.1.f [iii] port fast, BPDUguard, BPDUfilter
\n2.1.f [iv] loopguard, rootguard<\/code><\/p>\n

v5 Lab:
\n1.1.f Implement and troubleshoot spanning-tree
\n1.1.f [i] PVST+ \/ RPVST+ \/ MST
\n1.1.f [ii] switch priority, port priority, path cost, STP timers
\n1.1.f [iii] port fast, BPDUguard, BPDUfilter
\n1.1.f [iv] loopguard, rootguard<\/p>\n

Documentation:<\/p>\n

Catalyst 3750-X and 3560-X Software Configuration Guide, Release 15.0(1)SE,
\nChapter 22, Configuring Optional Spanning-Tree Features, pgs 22-1 to 22-19<\/p>\n

Books:<\/p>\n

CCIE Routing and Switching Exam Certification Guide 4th Ed; Chapter<\/p>\n

INE:<\/p>\n

Port Fast
\n– immediately brings an interface configured as an access or trunk port to the forwarding<\/p>\n

state
\n– bypasses the listening and learning states
\n– interfaces should not receive BPDUs<\/p>\n

conf t
\nint fa0\/1
\nspanning-tree portfast<\/p>\n

conf t
\nint fa0\/1
\nspanning-tree portfast trunk<\/p>\n

conf t
\nspanning-tree portfast default<\/p>\n

show spanning-tree int fa0\/1 portfast<\/p>\n

BPDU Guard
\n– shuts down ports that are in the Port Fast operational state when BPDUs are received
\n– port is placed in an err-disabled state
\n– can be configured to shutdown the the VLAN configured on the port instead of the port
\n– when configured globally, only affects ports in the Port Fast operational state
\n– can be configured on the interface without enabling Port Fast<\/p>\n

conf t
\nspanning-tree portfast bpduguard default
\nint fa0\/1
\nspanning-tree portfast<\/p>\n

conf t
\nint fa0\/1
\nspanning-tree bpduguard enable<\/p>\n

conf t
\nerrdisable detect cause bpduguard shutdown vlan<\/p>\n

BPDU Filter
\n– prevents interfaces that are in a Port Fast operational state from sending or receiving<\/p>\n

BPDUs
\n– if a BPDU is received, the interface loses its Port Fast operational state and BPDU<\/p>\n

filtering is disabled
\n– when configured globally, only affects ports in the Port Fast operational state
\n– can be configured on the interface without enabling Port Fast
\n– enabling BPDU filtering on an interface is the same as disabling spanning tree and can<\/p>\n

result in spanning tree loops<\/p>\n

conf t
\nspanning-tree portfast bpdufilter default
\nint fa0\/1
\nspanning-tree portfast<\/p>\n

conf t
\nint fa0\/1
\nspanning-tree bpdufilter enable<\/p>\n

Uplink Fast
\n– accelerates the choice of a new root port when a link or switch fails or when spanning<\/p>\n

tree reconfigures
\n– the root port transitions to the forwarding state immediately
\n– does not go through the listening or learning state
\n– when spanning tree reconfigures the new root port, the other interfaces flood the<\/p>\n

network with multicast packets
\n– the multicast packets include each address learned on the interface
\n– the multicast traffic can be reduced by reducing the max-update-rate parameter
\n– Uplink Fast is most useful at the access layer or the edge or the network
\n– Uplink Fast is not appropriate for backbone devices<\/p>\n

conf t
\nspanning-tree uplinkfast<\/p>\n

conf t
\nspanning-tree uplinkfast max-update-rate<\/p>\n

show spanning-tree summary<\/p>\n

Backbone Fast
\n– detects indirect failures in the core of the backbone
\n– complementary technology to the Uplink Fast feature
\n– optimizes the maximum-age timer, which controls the amount of time the switch stores<\/p>\n

protocol information received on the interface<\/p>\n

conf t
\nspanning-tree backbonefast<\/p>\n

show spanning-tree summary<\/p>\n

EtherChannel Guard
\n– detects and EtherChannel misconfiguration between the switch and the connected device
\n– places the interface in the error-disabled state<\/p>\n

conf t
\nspanning-tree etherchannel guard misconfig<\/p>\n

show spanning-tree summary
\nshow interfaces status err-disabled
\nshow etherchannel summary<\/p>\n

Root Guard
\n– configured on switches that are not supposed to be the root switch
\n– if spanning tree calculations select the switch as the root switch, root guard places<\/p>\n

the interface in the root-inconsistent (blocked) state, which prevents the switch from<\/p>\n

becoming the root switch or being in the path to the root<\/p>\n

conf t
\nint fa0\/1
\nspanning-tree guard root<\/p>\n

Loop Guard
\n– prevents alternate or root ports from becoming designated ports because of a failure<\/p>\n

that leads to a unidirectional link
\n– the feature is most effective when it is enable on the entire switching network
\n– prevents alternate and root ports from becoming designated ports
\n– BPDUs are not sent on alternate or root ports
\n– in MST mode, BPDUs are not sent on nonboundary ports only if the interface is blocked by<\/p>\n

loop guard in all MST instances
\n– on a boundary port, loop guard blocks the interface in all MST instances<\/p>\n

conf t
\nspanning-tree loopguard default<\/p>\n

show spanning-tree active
\nshow spanning-tree mst<\/p>\n

Default Optional Spanning-Tree configuration
\n– Port Fast: globally disabled
\n– BPDU filtering: globally disabled
\n– BPDU guard: globally disabled
\n– Uplink Fast: globally disabled
\n– Backbone Fast: globally disabled
\n– EtherChannel Guard: globally ENABLED
\n– Root Guard: disabled on all interfaces
\n– Loop Guard: disabled on all interfaces<\/p>\n

show spanning-tree active
\nshow spanning-tree detail
\nshow spanning-tree interface fa0\/1
\nshow spanning-tree mst interface fa0\/1
\nshow spanning-tree summary
\nshow spanning-tree summary totals<\/p>\n","protected":false},"excerpt":{"rendered":"

v5 Written: 2.1.f Implement and troubleshoot spanning-tree 2.1.f [i] PVST+ \/ RPVST+ \/ MST 2.1.f [ii] Switch priority, port priority, path cost, STP timers 2.1.f [iii] port fast, BPDUguard, BPDUfilter 2.1.f [iv] loopguard, rootguard v5 Lab: 1.1.f Implement and troubleshoot spanning-tree 1.1.f [i] PVST+ \/ RPVST+ \/ MST 1.1.f [ii] switch priority, port priority, path […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[30,11,15],"class_list":["post-79","post","type-post","status-publish","format-standard","hentry","category-ccie","tag-ccie","tag-route-switch","tag-stp"],"_links":{"self":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/79","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=79"}],"version-history":[{"count":2,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/79\/revisions"}],"predecessor-version":[{"id":227,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/79\/revisions\/227"}],"wp:attachment":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=79"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=79"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=79"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}