{"id":946,"date":"2011-09-07T22:35:00","date_gmt":"2011-09-07T14:35:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=946"},"modified":"2023-11-07T22:46:47","modified_gmt":"2023-11-07T14:46:47","slug":"cisco-stp-enhance","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/946","title":{"rendered":"Cisco STP Enhance"},"content":{"rendered":"\n

STP\u52a0\u5febconvergence
\u4e3b\u8981\u6709\u4ee5\u4e0b\u65b9\u6cd5
portfast<\/strong>:access-layer node
uplinkfast<\/strong>:access-layer uplinks
backbonefast<\/strong>:core-layer redundant backbone paths
ps:\u6b64\u4e09\u500b\u662f\u70ba\u4e86\u89e3\u6c7a802.1d\u6a19\u6e96\u7684\u7f3a\u9ede<\/p>\n\n\n\n

\u555f\u7528portfast
(config-if)#spanning-tree portfast<\/strong>
or global enable portfast
(config)# spanning-tree portfast default<\/strong>
\u5c07listen\u548clearn\u72c0\u614b\u6240\u9700\u6642\u9593\u7e2e\u5230\u6975\u77ed,\u56e0\u6b64\u611f\u61c9\u5230link up\u6642(workstation\u9023\u5165\u7db2\u8def)\u6703\u7acb\u523b\u5230forward\u72c0\u614b
\u3000\u53ef\u6e1b\u5c1130sec
\u3000\u6703\u4fdd\u6301loop\u5075\u6e2c\u529f\u80fd,\u82e5\u6709\u5075\u6e2c\u5230\u5247\u5c07port\u6539\u6210blocking state
\u3000\u555f\u52d5\u6216\u95dc\u9589\u6642\u4e0d\u6703\u767c\u9001tcnbpdu 
\u3000\u901a\u5e38\u7528\u5728\u9023\u63a5end user\u7684\u4ecb\u9762 
\u3000\u9810\u8a2d\u6bcf\u500b\u4ecb\u9762\u90fd\u95dc\u9589
Verifying method
\u3000show running-config interface < interface>
ps:
(config-if)#switchport host\u6703\u57f7\u884c\u4e09\u500b\u6307\u4ee4,\u5176\u4e2d\u4e00\u500b\u6703\u555f\u7528portfast
ps:
\u4e5f\u53ef\u652f\u63f4trunk port,\u53ef\u7e2e\u77edtrunk\u4ecb\u9762\u5230forward\u72c0\u614b\u4e4b\u6642\u9593
(config-if)#spanning-tree portfast trunk<\/p>\n\n\n\n


\u555f\u7528uplinkfast
(config)#spanning-tree uplinkfast [max-update-rate < pkts-per-second>]
\u7576root port\u65b7\u7dda\u5247\u99ac\u4e0a\u5c07alternate port\u5f9eblocking status\u8b8a\u6210forwarding status
\u3000\u53ef\u6e1b\u5c1130sec
\u3000alternate port\u662f\u6307\u4e0b\u500b\u6709\u6700\u4f4eroot path cost\u7684root port
\u3000\u6703\u8a18\u9304\u6bcf\u4e00\u689d\u5230root bridge\u7684\u8def\u5f91
\u3000\u6703\u4fee\u6539bridge priority\u70ba49152\u4ee5\u907f\u514d\u6210\u70baroot bridge,\u4e26\u628a\u6240\u6709port cost\u63d0\u9ad8\u81f33000\u4ee5\u6210\u70baend switch
\u3000\u4e0d\u53ef\u5728root bridge\u4e0a\u4f7f\u7528,\u901a\u5e38\u7528\u5728end switch(edge switch)\u4e0a
\u3000\u5229\u7528Dummy Frame\u53bb\u5075\u6e2c,\u6bcf\u79d2150frame
\u53c3\u6578\u8aaa\u660e\u5982\u4e0b:\u3000
[max-update-rate] \u53ef\u8a2d\u7bc4\u570d\u70ba0-65535,\u9810\u8a2d150,\u6bcf\u79d2\u901a\u77e5\u4e0a\u6e38switch\u8cc7\u8a0a\u7684packet\u6578\u91cf
\u3000\u4e3b\u8981\u50b3\u9001dummy multicast frames\u52300100.0ccd.cdcd
ex:\u555f\u7528uplinkfast
(config)# spanning-tree uplinkfast
# show spanning-tree uplinkfast
UplinkFast is enabled
Station update rate set to 150 packets\/sec.
UplinkFast statistics
Number of transitions via uplinkFast (all VLANs) : 2
Number of proxy multicast addresses transmitted (all VLANs) : 52
Name\u3000\u3000\u3000,Interface List
VLAN0001\u3000,Gi0\/1(fwd)
VLAN0010\u3000,Gi0\/1(fwd)
VLAN0100\u3000,Gi0\/1(fwd)<\/p>\n\n\n\n

\u555f\u7528backbonefast
(config)#spanning-tree backbonefast<\/strong>
\u5075\u6e2c\u9593\u63a5\u93c8\u8def\u6545\u969c,\u52a0\u5feb\u6536\u6582\u901f\u5ea6
\u3000\u5c07Max Age 20 sec\u6642\u9593\u7e2e\u77ed(\u5c07\u6536\u6582\u6642\u9593\u5f9e50\u79d2\u8b8a\u523030\u79d2)
\u3000\u6703\u555f\u7528RLQ protocol
ps:\u8a72\u7db2\u8def\u6240\u6709switch\u90fd\u555f\u7528backbonefast\u624d\u53ef\u6b63\u78ba\u7684\u904b\u4f5c,\u9810\u8a2d\u662f\u95dc\u9589<\/p>\n\n\n\n

… <\/p>\n\n\n\n

\u986f\u793auplinkfast\u72c0\u614b
#show spanning-tree uplinkfast<\/p>\n\n\n\n

\u986f\u793abackbonefast\u72c0\u614b
#show spanning-tree backbonefast<\/p>\n\n\n\n

……………………………………………………………………………………………………..<\/p>\n\n\n\n

RSTP Configuration<\/strong>
By default, a switch operates in PVST+ mode using traditional 802.1D STP.
Therefore, RSTP cannot be used until a different spanning-tree mode(MST or RPVST+) is enabled
ps:
RSTP is just the underlying mechanism<\/strong> that a spanning-tree mode can use to detect topology changes and converge a network into a loop-free topology<\/p>\n\n\n\n

enable the RPVST+ mode
Switch(config)# spanning-tree mode rapid-pvst<\/strong>
\u8981\u5c07\u8a72\u5340\u6240\u6709switch\u555f\u7528rstp,\u8a72\u5340\u624d\u6703\u5f62\u6210rstp\u7db2\u8def
ps:
After enable the RPVST+, the switch must begin supporting both RSTP and 802.1D STP neighbors. The switch can detect the neighbor’s STP type by the BPDU version that is received
ps
enable the PVST+ mode:#spanning-tree mode pvst<\/p>\n\n\n\n


To configure an RSTP edge port
Switch(config-if)# spanning-tree portfast<\/strong><\/p>\n\n\n\n

To force the port to act as a point-to-point link, if port is operating in half duplex mode
Switch(config-if)# spanning-tree link-type point-to-point<\/strong>
ps:
By default, RSTP automatically decides that a port is a point-to-point link if it is operating
in full-duplex mode<\/p>\n\n\n\n

shows information about the RSTP
#show spanning-tree [vlan < vlan-id> ]<\/strong>
ps
Switch# show spanning-tree vlan 171 \u70ba\u4f8b,\u756b\u9762\u5927\u81f4\u5982\u4e0b
VLAN0171
\u3000Spanning tree enabled protocol rstp<\/strong>
\u3000Root ID Priority 4267
\u3000\u3000\u3000\u3000\u3000\u3000Address 00d0.0457.38aa
\u3000\u3000\u3000\u3000\u3000\u3000Cost 3
\u3000\u3000\u3000\u3000\u3000\u3000Port 833 (Port-channel1)
\u3000\u3000\u3000\u3000\u3000\u3000Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32939 (priority 32768 sys-id-ext 171)
\u3000\u3000\u3000\u3000\u3000\u3000Address 0007.0d55.a800
\u3000\u3000\u3000\u3000\u3000\u3000Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
\u3000\u3000\u3000\u3000\u3000\u3000Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
—————- —- —- ——— ——– ——————————-
Gi7\/8 Desg FWD 4 128.392 P2p
Gi9\/6 Altn BLK 4 128.518 P2p Peer(STP)<\/strong>
Po1 Root FWD 3 128.833 P2p
Po2 Desg FWD 3 128.834 P2p
Po3 Desg FWD 3 128.835 P2p
\u8aaa\u660e\u5982\u4e0b
P2p denotes a point-to-point RSTP port type in which a full-duplex link connects two neighboring switches that both are running RSTP.
P2p Peer(STP), the port is a point-to-point type but the neighboring device is running traditional 802.1D STP<\/p>\n\n\n\n

………………………………………………………………………………………<\/p>\n\n\n\n

MST Configuration<\/strong>
1.
to must manually configure the MST configuration attributes on each switch in a region
ps:There is currently no method to propagate this information from one switch to another, as is done with a protocol such as VTP
2.
A switch cannot run both MST and PVST+ at the same time.<\/p>\n\n\n\n

…<\/p>\n\n\n\n

Enable MST on the switch:
Switch(config)# spanning-tree mode mst<\/strong>
After MST is enabled and configured, PVST+ operation stops and the switch changes to RSTP operation.<\/p>\n\n\n\n

MST configuration
1
Enter the MST configuration mode:
Switch(config)# spanning-tree mst configuration<\/strong>
2
Assign a “MST configuration name” for MST region
Switch(config-mst)# name < name><\/strong>
< name> :up to 32 characters
3
Assign a “region configuration revision number” for MST region
Switch(config-mst)# revision < version><\/strong>
< version> :0 to 65,535
4
Map VLANs to an MST instance in MST region:
Switch(config-mst)# instance < instance-id> vlan < vlan-list><\/strong>
< instance-id> :maximum of 16 MSTIs in each region.
The IST always exists as MSTI 0, leaving MSTIs 1-15 available for use.
< vlan-list> :1 to 4,094
ps:
by default, all VLANs are mapped to instance 0, the IST.
5
Show the pending changes you have made:
Switch(config-mst)# show pending<\/strong><\/p>\n\n\n\n

ex:
\u8a2d\u5b9amst,
region name=buildmst
revision=1
MST instance-to-VLAN mapping\u70ba msti1=vlan 51,52;msti2=vlan53-55
device1\u8a2d\u5b9a\u5982\u4e0b
device1(config)#spanning-tree mode mst
device1(config-mst)#spanning-tree mst configuration
device1(config-mst)#name buildmst
device1(config-mst)#revision 1 \/\/\u6240\u6709\u7684switch\u90fd\u8981\u76f8\u540c
device1(config-mst)#instance 1 vlan 51,52
device1(config-mst)#instance 2 vlan 53-55
device2\u8a2d\u5b9a\u5982\u4e0b
device2(config)#spanning-tree mode mst
device2(config-mst)#spanning-tree mst configuration
device2(config-mst)#name buildmst
device2(config-mst)#revision 1 \/\/\u6240\u6709\u7684switch\u90fd\u8981\u76f8\u540c
device2(config-mst)#instance 1 vlan 51,52
device2(config-mst)#instance 2 vlan 53-55<\/p>\n\n\n\n

…<\/p>\n\n\n\n

tune the parameters that MST uses when it interacts with CST or 802.1D.<\/p>\n\n\n\n

Set root bridge(macro).
Switch(config)# spanning-tree mst < instance-id> root < primary |secondary> [diameter < diameter>]<\/strong><\/p>\n\n\n\n

Set bridge priority.
Switch(config)# spanning-tree mst < instance-id> priority < bridge-priority><\/strong>
Set port cost.
Switch(config)# spanning-tree mst < instance-id> cost < cost><\/strong>
Set port priority.
Switch(config)# spanning-tree mst < instance-id> port-priority < port-priority><\/strong><\/p>\n\n\n\n

Set STP timers.
Switch(config)# spanning-tree mst hello-time < seconds>
Switch(config)# spanning-tree mst forward-time < seconds>
Switch(config)# spanning-tree mst max-age < seconds><\/strong><\/p>\n\n\n\n

…<\/p>\n\n\n\n

Displays mst configuration information
Switch#show spanning-tree mst configuration<\/strong>
ps:
\u756b\u9762\u5927\u81f4\u5982\u4e0b
Name [cisco]
Revision 1
Instance Vlans mapped
——– ———————————————————————
0 11-4094
1 1-10<\/p>\n\n\n\n


Displays MSTP instance
Switch#show spanning-tree mst < instance_number><\/strong>
ps:
Switch#show spanning-tree mst 1 \u70ba\u4f8b,\u756b\u9762\u5927\u81f4\u5982\u4e0b
###### MST01 vlans mapped: 1-10
Bridge address 00d0.00b8.1400 priority 32769 (32768 sysid 1)
Root this switch for MST01
Interface Role Sts Cost Prio.Nbr Status
—————- —- — ——— ——– ——————————–
Fa4\/4 Back BLK 1000 240.196 P2p
Fa4\/5 Desg FWD 200000 128.197 P2p
Fa4\/48 Boun FWD 200000 128.240 P2p Bound(STP)<\/p>\n\n\n\n


…<\/p>\n\n\n\n

\u53c3\u8003\u8cc7\u6599
http:\/\/life.iiietc.ncu.edu.tw\/xms\/read_attach.php?id=21303
http:\/\/baike.baidu.com\/view\/123854.htm
http:\/\/networking.ctocio.com.cn\/StandardProtocol\/164\/9080664.shtml
http:\/\/www.china-ccie.com\/ccie\/lilun\/switching\/switching.html#11
http:\/\/wenku.baidu.com\/view\/2b8f2f0790c69ec3d5bb7530.html<\/p>\n","protected":false},"excerpt":{"rendered":"

STP\u52a0\u5febconvergence\u4e3b\u8981\u6709\u4ee5\u4e0b\u65b9\u6cd5portfas …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[34],"tags":[],"class_list":["post-946","post","type-post","status-publish","format-standard","hentry","category-cisco-layer2"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=946"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/946\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}