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SPANNING TREE PROTOCOL(STP)THC TP MNG MY TNHNhc li: Hub, Repeater, Bridge, Switch, Router1Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh2Mc tiuVai tr ca ng d phng trong mng hi t.Hn ch ca m hnh mng vi ng d phng.Hot ng ca giao thc STPKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh3D phng

One BridgeRedundant BridgesKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh4Phn loi traffic (Tng 2)UnicastMulticastBroadcast

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh5M hnh Switch d phng

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh6Broadcast stormKhi mt thit b mng ni b pht sinh ra mt gi in broadcast, gi tin ny s c truyn qua li gia cc Switch lin tc, lm cho cc Switch trn b nh.

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh7Multiple frame transmissionsCc gi tin unicast s b nhn ra lm nhiu gi tin ging nhau v cng truyn n thit b ch. iu ny lm tn ti nguyn v d dng gy ra li khi truyn v nhiu cc giao thc ch mong mun nhn c mt gi tin trong mt ln truyn.

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh8MAC address table instability chuyn cc gi tin gia cc interaface, switch s da vo MAC table. Tuy nhin, vic nhiu gi tin ging nhau c nhn ti cc port khc nhau s lm cho switch phi cp nht MAC table lin tc, gy ra s mt n nh.Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh9Gii quytSPANNING TREE PROTOCOLCh s dng cc ng d phng khi cn thit. Vic la chn ng no s c s dng trnh vic loop cc gi tin ny s c giao thc Spanning Tree.

9Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh10Gii thiu STPIEEE 802.1D Spanning-Tree ProtocolS dng cho bridge v switch xy dng mng shortest path trnh loop bng thut ton spanning-treeng i ngn nht da trn link cost cng dnLink cost da trn tc ca link.

Gii thiu STPSpanning-Tree Protocol thit lp mt root node, gi l root bridgeXy dng hnh mng c mt con ng n c tt c cc nt mng.Cy kt qu c gc l root bridge.Nhng ng d phng khng thuc shortest path tree s b block.D liu nhn trn nhng ng b block s b xa.Nhng ng c kh nng gy ra loop b block hnh mng trnh loop.

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh11Bridge Protocol Data Units (BPDUs)Spanning-Tree Protocol cn cc thit b mng trao i tin nhn to nn hnh mng trnh loop.Nhng tin nhn gi l Bridge Protocol Data Units (BPDUs)Nhng link gy ra loop s b a vo trng thi blocking.BPDUs vn c nhn blocked portsKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh12Bridge Protocol Data Units (BPDUs)Chc nng ca BPDUs:Chn ra switch lm root cho spanning tree.Tnh shortest path t switch khc n root switch.Ch ra designated switch cho mi nhnh LAN.Designated switch x l thng tin gia LAN v root bridge. Chn ra root port (nm trn non-root switch)y l cng c ng i tt nht n root switch. Chn ra port nm trong spanning tree, gi l designated portsNon-designated port blockedKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh13Root Ports, Designated Ports, & Non-Designated Ports

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh14Thng tin trong BPDUs

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh15Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh16Bridge ID (BID)BID s dng bu chn root bridge (BID Min).

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh17Bridge ID (BID)ALSwitch#show spanning-tree

VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32768 Address 0003.e334.6640 Cost 19 Port 23 (FastEthernet0/23) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 000b.fc28.d400 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300

Interface Port ID Designated Port IDName Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr---------------- -------- --------- --- --------- -------------------- --------Fa0/23 128.23 19 FWD 0 32768 0003.e334.6640 128.25

ALSwitch#Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh18Path cost4 Mbps 250 (cost)10 Mbps 100 (cost)16 Mbps 62 (cost)45 Mbps 39 (cost)100 Mbps 19 (cost)155 Mbps 14 (cost)622 Mbps 6 (cost)1 Gbps 4 (cost)10 Gbps 2 (cost)

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh19Th t quyt nh1 - Lowest BID2 - Lowest Path Cost to Root Bridge3 - Lowest Sender BID4 - Lowest Port ID Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh20STP ConvergenceB1 Bu chn Root BridgeB2 Bu chn Root PortsB3 Bu chn Designated Ports

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh21B1 Bu chn Root Bridge

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh22B1 Bu chn Root Bridge2950#show spanning-tree

VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32768 Address 0003.e334.6640 Cost 19 Port 23 (FastEthernet0/23) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 000b.fc28.d400 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300

Interface Port ID Designated Port IDName Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr---------------- -------- --------- --- --------- -------------------- --------Fa0/23 128.23 19 FWD 0 32768 0003.e334.6640 128.25ALSwitch#Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh23B2 Bu chn Root PortsMi non-root bridge s bu chn 1 root port.Root port l port gn root bridge nht (da vo root path cost).Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh24B2 Bu chn Root Ports

BPDUCost=0BPDUCost=0BPDUCost=0+19=19BPDUCost=0+19=19BPDUCost=19BPDUCost=38 (19+19)BPDUCost=38 (19+19)BPDUCost=19Root PortRoot PortKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh25B2 Bu chn Designated PortsDesignated port l port gi nhn d liu gia segment v broot bridge.Mi segment c 1 designated port, chn da trn root path cost.Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh26B2 Bu chn Designated Ports

Root PortRoot PortSegment 1Segment 2Segment 3Root Path Cost = 0Root Path Cost = 0Root Path Cost = 19Root Path Cost = 19Root Path Cost = 19Root Path Cost = 19Designated PortDesignated Port

32,768.BB-BB-BB-BB-BB-BB32,768.CC-CC-CC-CC-CC-CCDesignated PortNon-Designated PortPort Cost/Port IDKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh27

path cost v port priority bng nhau Port ID: Port 0/1 < Port 0/20/1ForwardingBlocking

0/2XTrng thi Spanning-Tree Port

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh28BlockingPort ch nhn BPDUsD liu b loi b v khng hc a ch mi. chuyn qua trng thi ny mt 20s.ListeningXc nh tt c ng i n root bridge.ng i n root bridge khng tn t chi ph nht blocked stateBPDUs.Khng chuyn d liu v khng hc a ch MAC.Thi gian listening gi l forward delay: 15s.Trng thi Spanning-Tree PortKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh29LearningKhng chuyn d liu, hc a ch MAC.Thi gian learning cng gi l forward delay: 15s. BPDUsForwardingChuyn d liu v tip tc hc a ch MAC.BPDUs.Disabled Ngi qun tr tt port hoc port b h.Trng thi Spanning-Tree PortKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh30Khc phc s cKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh31

HubKhc phc s cKhoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh32

HubHubX FailsKhng thy BPDU t Cat-BBlockingListening Learning Forwarding 33Hi & p

Khoa Cng ngh thng tin - i hc Khoa hc t nhin TP H Ch Minh