[CCNA] Switch

                   #### Root-brige와 Non Root-bridge 구간 장애 발생시 동작과정

          ## 장애 발생시 동작과정 확인

-Block  (장애발생시) [BLK]

-Listening : (15초) [LIS]

-Learning  : (15초) [LRN]

-Forward : 총 30초 소요 [FWD]

SW1# debug spanning-tree events

Spanning Tree event debugging is on

SW1(config)# interface fa0/24

SW1(config-if)# shutdown

        **** SW1에서 Debug 정보 확인 ****

03:15:40: STP: VLAN0001 new root port Fa0/20, cost 38   <-- Fa0/24장애 발생시 Fa0/20가 Root-port로 전환

03:15:40: STP: VLAN0001 Fa0/20 -> listening   <--- Blockport가 해당 Port를 Forwarding실시전 Loop체크

03:15:55: STP: VLAN0001 Fa0/20 -> learning   <--- 데이터 통신을위한 Mac-address 학습

03:16:10: STP: VLAN0001 Fa0/20 -> forwarding   <--- 해당 Port가 Forwarding상태로 전환

          ## 장애 복구시 동작과정 확인

SW1(config)# interface fa0/24

SW1(config-if)# no shutdown

        **** SW1에서 Debug 정보 확인 ****

00:46:46: set portid: VLAN0001 Fa0/24: new port id 801A

00:46:46: STP: VLAN0001 Fa0/24 -> listening

00:46:47: STP: VLAN0001 new root port Fa0/24, cost 19

00:46:47: STP: VLAN0001 sent Topology Change Notice on Fa0/24

00:46:47: STP: VLAN0001 Fa0/20 -> blocking

00:47:01: STP: VLAN0001 Fa0/24 -> learning

00:47:16: STP: VLAN0001 Fa0/24 -> forwarding

=========================================================================================================

         # Root-brige와 Backup Root-bridge 구간 장애 발생시 동작과정

-Block (20간 유지 : Max-age) [BLK]

-Listening : (15초) [LIS]

-Learning  : (15초) [LRN]

-Forward : 총 50초 소요 [FWD]

SW1# debug spanning-tree events

Spanning Tree event debugging is on

SW2(config)# interface fa0/22

SW2(config-if)# no shutdown

        **** SW1에서 Debug 정보 확인 ****

00:58:08: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:10: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:12: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:14: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:16: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:18: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:20: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:22: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:24: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:26: STP: VLAN0001 Fa0/20 -> listening

00:58:26: STP: VLAN0001 heard root 16385-000f.248a.3480 on Fa0/20

00:58:26: STP: VLAN0001 Topology Change rcvd on Fa0/20

00:58:26: STP: VLAN0001 sent Topology Change Notice on Fa0/24

00:58:41: STP: VLAN0001 Fa0/20 -> learning

00:58:56: STP: VLAN0001 sent Topology Change Notice on Fa0/24

00:58:56: STP: VLAN0001 Fa0/20 -> forwarding

Switch(config)# spanning-tree vlan x hello-time [초 : Default 2초]

Switch(config)# spanning-tree vlan x forward-time [초 : Default 15초]

Switch(config)# spanning-tree vlan x max-age [초 : Default 20초]

[PRE CONFIG]

           # SW1

enable

configure terminal

!

no ip domain-lo

!

line console 0

 logging sy

 exec-timeout 0 0

!

hostname SW1

!

interface vlan 1

 no shutdown

 ip address 192.168.1.1  255.255.255.0

!

interface range fa0/1 , fa0/23

 shutdown

!

            # SW2

enable

configure terminal

!

no ip domain-lo

!

line console 0

 logging sy

 exec-timeout 0 0

!

hostname SW2

!

interface vlan 1

 no shutdown

 ip address 192.168.1.2  255.255.255.0

!

interface range fa0/1 , fa0/21

 shutdown

!

            # SW3

enable

configure terminal

!

no ip domain-lo

!

line console 0

 logging sy

 exec-timeout 0 0

!

hostname SW3

!

interface vlan 1

 no shutdown

 ip address 192.168.1.3  255.255.255.0

!

interface range fa0/1 , fa0/19

 shutdown

!