VRRP Preempt 동작 과정

1. VRRP(Virtual Router Redundancy Protocol) Preempt 동작 과정

1) 구성도 및 Configuration

< R1 : 설정 >
set bridge-domains VLAN10 vlan-id 10
set bridge-domains VLAN10 routing-interface irb.10
set interfaces ge-0/0/1 unit 0 family bridge interface-mode trunk
set interfaces ge-0/0/1 unit 0 family bridge vlan-id-list 10
set interfaces irb unit 10 family inet address 10.0.0.2/24 vrrp-group 10 virtual-address 10.0.0.1
set interfaces irb unit 10 family inet address 10.0.0.2/24 vrrp-group 10 priority 120
set interfaces irb unit 10 family inet address 10.0.0.2/24 vrrp-group 10 accept-data
set interfaces irb unit 10 family inet address 10.0.0.2/24 vrrp-group 10 preempt	## Default 값

< R2 : 설정 >
set bridge-domains VLAN10 vlan-id 10
set bridge-domains VLAN10 routing-interface irb.10
set interfaces ge-0/0/1 unit 0 family bridge interface-mode trunk
set interfaces ge-0/0/1 unit 0 family bridge vlan-id-list 10
set interfaces irb unit 10 family inet address 10.0.0.3/24 vrrp-group 10 virtual-address 10.0.0.1
set interfaces irb unit 10 family inet address 10.0.0.3/24 vrrp-group 10 priority 100
set interfaces irb unit 10 family inet address 10.0.0.3/24 vrrp-group 10 accept-data
set interfaces irb unit 10 family inet address 10.0.0.3/24 vrrp-group 10 preempt	## Default 값

< SW : 설정 >
set bridge-domains VLAN10 vlan-id 10
set interfaces ge-0/0/0 unit 0 family bridge interface-mode trunk
set interfaces ge-0/0/0 unit 0 family bridge vlan-id-list 10
set interfaces ge-0/0/1 unit 0 family bridge interface-mode trunk
set interfaces ge-0/0/1 unit 0 family bridge vlan-id-list 10
set interfaces ge-0/0/2 unit 0 family bridge interface-mode access
set interfaces ge-0/0/2 unit 0 family bridge vlan-id 10

 

2) VRRP Preempt 동작 과정

• VRRP 동작 과정은 이미 알고 있다는 가정하에 Master 장애 발생한 다음부터 설명 시작

• R1 irb.10을 Disable하면 VRRP 동작을 하지 않으며 ge-0/0/1을 Disable하면 Init 상태로 유지
• R1 irb.10 인터페이스가 아닌 ge-0/0/1 물리적 인터페이스가 Down되었으면 R1 ARP Table에 10.0.0.10 Entry 제거

 

• 처음에 Master로 동작하던 장비의 장애를 복구하여 VRRP 프로세스가 재시작하고 Backup으로 대기
  
  • 인터페이스 'shutdown/no shutdown'을 하거나 '케이블을 다시 연결'할 경우에도 VRRP 프로세스가 새로 시작 
  • 일반적으로 Backup 상태에서 Dead Interval 동안 대기(Vendor 또는 장비마다 상이하므로 확인 필요)
• 대기 시간 동안 수신한 VRRP Advertisement의 Priority보다 자신의 Priority 값이 낮으면 VRRP Advertisement를 전송하지 않고 Backup으로 유지

 

• 대기 시간 동안 수신한 VRRP Advertisement가 없거나 수신한 VRRP Advertisement의 Priority보다 자신의 Priority 값이 높으면 VRRP Advertisement를 전송하고 Master로 동작
• Master 장비가 Advertisement Interval마다 VRRP Advertisement를 전송
• VRRP Master를 다시 점유하기 위한 조건
  • 대기 시간 동안 수신되는 VRRP Advertisement가 미존재
  • 대기 시간 동안 수신되는 VRRP Advertisement가 존재할 경우, Preempt Enable 및 수신되는 VRRP Advertisement의 Priority보다 자신의 Priority 값이 높아야 가능