Packet tracer 5.0 Experiment (5) Fast Spanning Tree Configuration

I. Lab Objectives

• Understand the working principle of the Spanning Tree Protocol;
• Master the basic configuration method of RSTP for the fast generation Tree Protocol;

 

Ii. Lab background

In order to carry out computer teaching and network work, the school has established a computer classroom and an office area. The computer networks of these two locations are connected to each other through two switches to form an internal campus network, to improve network reliability, as a network administrator, you need to use two links to interconnect the vswitch. Now, you need to make proper configurations on the vswitch so that the network can avoid loops.

 

Iii. Technical Principles

The Spanning Tree Protocol (spanning-tree) is used to provide redundant backup links in the switching network and solve the loop problem in the switching network;

The Spanning Tree Protocol uses SPAAlgorithmTo generate a tree network without loops in a network with an exchange loop. This algorithm is used to logically disconnect the redundant backup link of the switching network. When the master link fails, it can automatically switch to the backup link to ensure normal data forwarding;

Spanning Tree Protocol versions: STP, RSTP (fast spanning tree), and MSTP (Multi-Spanning Tree Protocol );

The Spanning Tree Protocol has a long convergence time. It takes 50 seconds to switch from the primary link to the backup link;

Based on the Spanning Tree Protocol, the quick Spanning Tree Protocol adds two port roles: Replace the port and backup port as the redundant ports of the root port and the specified port respectively. When the root port or specified port fails, the redundant port does not require a convergence time of 50 seconds. You can directly switch to the replacement port or backup port, this enables fast convergence of the RSTP Protocol within 1 second.

 

Iv. Experiment steps

Lab Topology

If the STP protocol is enabled by default, the BPDU protocol data units are transmitted between the two switches, and the root switch and root port are selected to determine the port forwarding status. The port marked as orange is in the block blocking status.

Set RSTP

View the show spanning-tree status of the vswitch to check the status of the root switch and the root port;

You can change the role of the root switch by changing the priority spanning-tree VLAN * priority 4096 of the switch generation tree;

S1:

 Switch> enswitch # conf tenter configuration commands, one per line. End with cntl/Z. Switch (config) # hostname s1s1 (config) # ends1 # % SYS-5-CONFIG_ I: configured from console by Console S1 # Show spanning-tree // view switch spanning-tree status vlan0001 Spanning Tree enabled protocol IEEE root ID priority 32769 address 0060.5c36.5620 cost 19 Port 1 (fastethernet0/1) hello time 2 sec Max age 20 sec forward delay 15 sec bridge ID priority 32769 (Priority 32768 sys-ID-ext 1) address 0060.7078.8bde Hello time 2 sec Max age 20 sec forward delay 15 sec aging time 20 interface role STS cost PRIO. NBR typ E ---------------- ---- --- --------- -------- failed fa0/10 desg fwd 19 128.10 p2pfa0/1 root FWD 19 128.1 p2pfa0/2 altn BLK 19 128.2 p2ps1 # conf tenter configuration commands, one per line. end with cntl/Z. s1 (config) # interface fa0/10s1 (config-If) # switchport access VLAN 10 // divide fa0/10 into VLAN 10% access VLAN does not exist. creating VLAN 10s1 (config-If) # exits1 (config) # Interface Range fa0/1-2 // set fa0/1, fa0/2 port status to trunk mode S1 (config-if-range) # switchport mode trunk % LINEPROTO-5-UPDOWN: line protocol on interface fastethernet0/1, changed state to down % LINEPROTO-5-UPDOWN: Line protocol on interface fastethernet0/1, changed state to up % LINEPROTO-5-UPDOWN: Line protocol on interface fastethernet0/2, changed state to down % LINEPROTO-5-UPDOWN: Line protocol on interface fastethern Et0/2, changed state to ups1 (config-if-range) # exits1 (config) # spanning-tree mode? // Set spanning-tree to RSTP mode pvst per-VLAN spanning tree mode rapid-pvst per-VLAN Rapid Spanning Tree modes1 (config) # spanning-tree mode rapid-pvst S1 (config )#

S2:

Switch> enswitch # Show spanning-tree vlan0001 Spanning Tree enabled protocol IEEE root ID priority 32769 address 0060.5c36.5620 This bridge is the root // root Switch Hello time 2 sec Max age 20 sec forward delay 15 sec bridge ID priority 32769 (Priority 32768 sys-ID-ext 1) address 0060.5c36.5620 Hello time 2 sec Max age 20 sec forward delay 15 sec aging time 20 interface role STS cost PRIO. NBR type ---------------- ---- --- --------- -------- failed fa0/1 desg fwd 19 128.1 p2pfa0/2 desg fwd 19 128.2 p2pfa0/10 desg fwd 19 128.10 p2pswitch # % LINEPROTO-5-UPDOWN: line protocol on interface fastethernet0/1, changed state to down % LINEPROTO-5-UPDOWN: Line protocol on interface fastethernet0/1, changed state to up % LINEPROTO-5-UPDOWN: Line protocol on interface fastethernet0/2, changed state to down % LINEPROTO-5-UPDOWN: Line protocol on interface fastethernet0/2, changed state to upswitch # Switch # conf tenter configuration commands, one per line. end with cntl/Z. switch (config) # hostname s2s2 (config) # interface fa0/10s2 (config-If) # switchport access VLAN 10% access VLAN does not exist. creating VLAN 10s2 (config-If) # exits2 (config) # interface range fa0/1-2s2 (config-if-range) # switchport mode trunk S2 (config-if-range) # exits2 (config) # spanning-tree mode rapid-pvst S2 (config )#

 

V. Test

When the main link is down, It can automatically switch to the backup link to ensure normal data forwarding.

Shutdown fa0/1 on S2

Switch # conf tenter configuration commands, one per line. end with cntl/Z. switch (config) # intswitch (config) # interface fa0/1 switch (config-If) # shuswitch (config-If) # shutdown // shutdown fa0/1 port switch (config-If) # % link-5-changed: interface fastethernet0/1, changed state to administratively down % LINEPROTO-5-UPDOWN: line protocol on interface fastethernet0/1, changed state to downswitch # Show spanning-treeVLAN0001 Spanning Tree enabled protocol RSTP root ID priority 32769 address 0001.63e2.4a7a this bridge is the root Hello time 2 sec Max age 20 sec forward delay 15 sec bridge ID priority 32769 (priority 32768 sys-ID-ext 1) address 0001.63e2.4a7a Hello time 2 sec Max age 20 sec forward delay 15 sec aging time 20 interface role STS cost PRIO. NBR type ---------------- ---- --- --------- -------- failed fa0/1 desg fwd 19 128.1 p2pfa0/2 desg fwd 19 128.2 p2pvlan0010 Spanning Tree enabled protocol RSTP root ID priority 32778 address limit this bridge is the root hello time 2 sec Max age 20 sec forward delay 15 sec bridge ID priority 32778 (Priority 32768 sys-ID-ext 10) address 0001.63e2.4a7a Hello time 2 sec Max age 20 sec forward delay 15 sec aging time 20 interface role STS cost PRIO. NBR type ---------------- ---- --- --------- ------------------------------------ fa0/1 desg fwd 19 128.1 p2pfa0/2 desg fwd 19 128.2 p2pfa0/10 desg fwd 19 128.10 p2pswitch #

PC1:

 
PC> ipconfigip address ......................: 192.168.1.2subnet mask .....................: 255.255.255.0default gateway .................: 192.168.1.1pc> Ping-T 192.168.1.3pinging 192.168.1.3 with 32 bytes of data: reply from 192.168.1.3: bytes = 32 time = 78 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 94 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 78 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 78 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 78 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 94 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 93 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 93 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 62 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 94 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 79 Ms TTL = 128 reply from 192.168.1.3: bytes = 32 time = 94 Ms TTL = 128
......
 

Test results: