VRRP

Configuring VRRP:

     ·         Virtual Router Redundancy Protocol

·         Industry Standard protocol

·         Default priority is 100

·         Default MAC address for Cisco: 0000.5e00.01xx -> xx is the VRRP Group number

·         There is no preemption by default

·         Let me take a small topology to configure VRRP

R1----LAN------R2-------LAN------R4 (10.1.124.0/24)

R1----Ser1/0---------------------------Ser1/0----R3

10.1.1.1                                   10.1.1.3

 

 

Configuring VRRP between R1 and R2:

 

R1(config-if)#do show run int fa0/0

Building configuration...

 

Current configuration : 160 bytes

!

interface FastEthernet0/0

 ip address 10.1.124.1 255.255.255.0

 duplex auto

 speed auto

 vrrp 1 ip 10.1.124.10

 vrrp 1 priority 150

 end

 

R1(config-if)#

 

R2(config-if)#do show run int fa0/0

Building configuration...

 

Current configuration : 118 bytes

!

interface FastEthernet0/0

 ip address 10.1.124.2 255.255.255.0

 duplex auto

 speed auto

 vrrp 1 ip 10.1.124.10

end

 

R2(config-if)#

R4#show run int fa0/0

Building configuration...

 

Current configuration : 95 bytes

!

interface FastEthernet0/0

 ip address 10.1.124.4 255.255.255.0

 duplex auto

 speed auto

end

 

R4#

 

Verification:

 

R1(config-if)#do show vrrp

FastEthernet0/0 - Group 1

  State is Master

  Virtual IP address is 10.1.124.10

  Virtual MAC address is 0000.5e00.0101

  Advertisement interval is 1.000 sec

  Preemption enabled

  Priority is 150

  Master Router is 10.1.124.1 (local), priority is 150

  Master Advertisement interval is 1.000 sec

  Master Down interval is 3.414 sec

 

R1(config-if)#

 

R2(config-if)#do show vrrp

FastEthernet0/0 - Group 1

  State is Backup

  Virtual IP address is 10.1.124.10

  Virtual MAC address is 0000.5e00.0101

  Advertisement interval is 1.000 sec

  Preemption enabled

  Priority is 100

  Master Router is 10.1.124.1, priority is 150

  Master Advertisement interval is 1.000 sec

  Master Down interval is 3.609 sec (expires in 3.081 sec)

 

R2(config-if)#

 

R4#ping 10.1.124.10

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.124.10, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/35/80 ms

R4#

R4#telnet 10.1.124.10

Trying 10.1.124.10 ... Open

 

 

User Access Verification

 

Password:

R1>

 

Observation:

·         VRRP is up between R1 and R2

·         R1 is Master router

·         R2 is ackup router

·         That is the reason when R4 tried to telnet 10.1.124.10, it went to R1

 

·         Now, let me shut the interface in R1 router and see

 

R1(config)#int fa0/0

R1(config-if)#shut

R1(config-if)#

*Mar  1 01:57:54.759: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Master -> Init

R1(config-if)#

*Mar  1 01:57:56.759: %LINK-5-CHANGED: Interface FastEthernet0/0, changed state to administratively down

*Mar  1 01:57:57.759: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down

R1(config-if)#

 

R2(config-if)#

*Mar  1 01:57:35.759: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Backup -> Master

R2(config-if)#

 

R1(config-if)#do show vrrp

FastEthernet0/0 - Group 1

  State is Init

  Virtual IP address is 10.1.124.10

  Virtual MAC address is 0000.5e00.0101

  Advertisement interval is 1.000 sec

  Preemption enabled

  Priority is 150

  Master Router is unknown, priority is unknown

  Master Advertisement interval is unknown

  Master Down interval is unknown

 

R1(config-if)#

 

R2(config-if)#do show vrrp

FastEthernet0/0 - Group 1

  State is Master

  Virtual IP address is 10.1.124.10

  Virtual MAC address is 0000.5e00.0101

  Advertisement interval is 1.000 sec

  Preemption enabled

  Priority is 100

  Master Router is 10.1.124.2 (local), priority is 100

  Master Advertisement interval is 1.000 sec

  Master Down interval is 3.609 sec

 

R2(config-if)#

 

R4#ping 10.1.124.10

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.124.10, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/34/84 ms

R4#telnet 10.1.124.10

Trying 10.1.124.10 ... Open

 

 

User Access Verification

 

Password:

R2>

 

Observation:

·         Shut the Fa0/0 interface in R1

·         Now, R2 is Active router

·         R1 is Standby router

·         That is the reason when R4 tried to telnet 10.1.124.10, it went to R2

 

·         Now, let me Bring back R1 as Active

 

R1(config-if)#no shut

R1(config-if)#

*Mar  1 01:59:18.875: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Init -> Backup

R1(config-if)#

*Mar  1 01:59:20.863: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up

*Mar  1 01:59:21.863: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

R1(config-if)#

*Mar  1 01:59:22.291: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Backup -> Master

R1(config-if)#

 

R2(config-if)#

*Mar  1 01:59:02.671: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Master -> Backup

R2(config-if)#

 

·         Now, let me configure interface tracking in VRRP:

 

R1(config)#track 1 interface serial 1/0 line-protocol

 

R1(config-track)#int fa0/0

R1(config-if)#vrrp 1 track 1 decrement 51

R1(config-if)#

 

·         When Serial1/0 interface goes down, track 1 will go down.

·         If track 1 goes down, R1’s VRRP priority would become less 51, i.e., 99

·         Let me check this by shutting the Serial1/0 interface in R1.

 

 

R1(config-if)#int ser1/0

R1(config-if)#shut

R1(config-if)#

*Mar  1 02:03:51.791: %TRACKING-5-STATE: 1 interface Se1/0 line-protocol Up->Down

R1(config-if)#

*Mar  1 02:03:53.779: %LINK-5-CHANGED: Interface Serial1/0, changed state to administratively down

*Mar  1 02:03:54.779: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/0, changed state to down

R1(config-if)#

*Mar  1 02:03:55.331: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Master -> Backup

R1(config-if)#do show vrrp

FastEthernet0/0 - Group 1

  State is Backup

  Virtual IP address is 10.1.124.10

  Virtual MAC address is 0000.5e00.0101

  Advertisement interval is 1.000 sec

  Preemption enabled

  Priority is 99  (cfgd 150)

    Track object 1 state Down decrement 51

  Master Router is 10.1.124.2, priority is 100

  Master Advertisement interval is 1.000 sec

  Master Down interval is 3.414 sec (expires in 3.230 sec)

 

R1(config-if)#

 

R2(config-if)#

*Mar  1 02:03:35.627: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Backup -> Master

R2(config-if)#

 

Observation:

·         Interface tracking is configured in R1, for Ser1/0

·         Its configured in such a way that if Ser1/0 goes down, track 1 will be down and R1’s VRRP will decrement by 51 and becomes 99

·         Once the track 1 down, R1’s VRRP priority became 99 and R2 became Active.

 

 

R1(config-if)#no shut

R1(config-if)#

*Mar  1 02:05:06.891: %TRACKING-5-STATE: 1 interface Se1/0 line-protocol Down->Up

R1(config-if)#

*Mar  1 02:05:07.211: %LINK-3-UPDOWN: Interface Serial1/0, changed state to up

*Mar  1 02:05:08.211: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/0, changed state to up

R1(config-if)#

*Mar  1 02:05:09.415: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Backup -> Master

R1(config-if)#

 

R2(config-if)#

*Mar  1 02:04:49.767: %VRRP-6-STATECHANGE: Fa0/0 Grp 1 state Master -> Backup

R2(config-if)#