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HSRP Help Please

nkillgore
Level 1
Level 1

Can someone help with this? is R1 or R2 forwarding traffic if everything is up? What does "track 1" do?

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

ip address 158.112.127.225 255.255.255.240 secondary

ip address 192.168.181.3 255.255.255.0 secondary

ip address 192.168.180.3 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 90

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 80

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 100

media-type rj45

no mop enabled

R2

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.180.2 255.255.255.0 secondary

ip address 192.168.181.2 255.255.255.0 secondary

ip address 192.168.182.2 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 95

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 1000

media-type rj45

no mop enabled

Thanks

1 Accepted Solution

Accepted Solutions

Bilal Nawaz
VIP Alumni
VIP Alumni

Please see:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094e8c.shtml

standby track

command allows you to specify another interface on the router for the HSRP process to monitor in order to alter the HSRP priority for a given group. If the line protocol of the specified interface goes down, the HSRP priority is reduced. This means that another HSRP router with higher priority can become the active router if that router has standby preempt enabled.

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_configuration_example09186a0080bc1d0c.shtml is more relevant to your configuration

R2 is active for standby group 2 and 3 it will be forwarding traffic (although I think there is a misconfiguration in this).

If the tracked object was to go down on R2 it will definitely still be active for standby group 3, since it will still have a better priority value of 95 - 10 = 85 compared with R1, 80. It may still be active for standby group 2 (they'll be the same and will go down to tiebreakers) which seems to nullify the purpose of the track command. Because if the priority will always be higher, whether the tracked object goes down or not, there will be no point in it as it wont make a difference in which is the active gateway....

The default standby priority value is 100, the track command will monitor another interface to see if its in the up state, if it goes down then the track command decrements the value of the priority by specified number in the command. Although, there may be some misconfiguration on R1 or R2 in your example. I have added a config in blue below to give you an example of how this works.

The command highlighted in Red and blue specify the priority, lets take R1 Standby 2 commands compared with R2

R1 has priority 90 whereas R2 has priority 95, so R2 wins!

On R2 you are tracking 1 (say that interface was to go down) HSRP process would decrement the priority by 10 so all in all R2 will have a priority of 85 - since preempt is enabled then R1 would take over because of the priority of 90. Same vice versa

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

standby 2 ip 192.168.182.1

standby 2 priority 90

standby 2 preempt

standby 2 track 1 decrement 10

R2

interface GigabitEthernet0/0

description Inside Interface

standby 2 ip 192.168.182.1

standby 2 priority 95

standby 2 preempt

standby 2 track 1 decrement 10

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

I would configure your R1 and R2 like this:

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

ip address 158.112.127.225 255.255.255.240 secondary

ip address 192.168.181.3 255.255.255.0 secondary

ip address 192.168.180.3 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 100               Default value

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 100               Default value

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 100

media-type rj45

no mop enabled

R2

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.180.2 255.255.255.0 secondary

ip address 192.168.181.2 255.255.255.0 secondary

ip address 192.168.182.2 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 95

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 95

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 1000

media-type rj45

no mop enabled

This would mean that R1 will be the active gateway because of the priority 100 (highest wins)

Only until the tracked object goes 'down' (all based on the status of the object).

The priority on R1 will then be 100 - 10 = 90.

Since preempt is enabled R2 will win since it has 95. This is then the active gateway.

In this case you may not need the track command under R2 since it wont be active all the time.

When R1 recovers and the tracked item is back 'up' then everything goes back to normal.

R1 then has the original priority of 100, and becomes the active gateway once again.

Or the otherway round with R2 being active. Or even R1 being active for one of the groups and R2 being active for the other.

Hope this helps

Please rate useful posts & remember to mark any solved questions as answered. Thank you.

View solution in original post

4 Replies 4

Bilal Nawaz
VIP Alumni
VIP Alumni

Please see:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094e8c.shtml

standby track

command allows you to specify another interface on the router for the HSRP process to monitor in order to alter the HSRP priority for a given group. If the line protocol of the specified interface goes down, the HSRP priority is reduced. This means that another HSRP router with higher priority can become the active router if that router has standby preempt enabled.

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_configuration_example09186a0080bc1d0c.shtml is more relevant to your configuration

R2 is active for standby group 2 and 3 it will be forwarding traffic (although I think there is a misconfiguration in this).

If the tracked object was to go down on R2 it will definitely still be active for standby group 3, since it will still have a better priority value of 95 - 10 = 85 compared with R1, 80. It may still be active for standby group 2 (they'll be the same and will go down to tiebreakers) which seems to nullify the purpose of the track command. Because if the priority will always be higher, whether the tracked object goes down or not, there will be no point in it as it wont make a difference in which is the active gateway....

The default standby priority value is 100, the track command will monitor another interface to see if its in the up state, if it goes down then the track command decrements the value of the priority by specified number in the command. Although, there may be some misconfiguration on R1 or R2 in your example. I have added a config in blue below to give you an example of how this works.

The command highlighted in Red and blue specify the priority, lets take R1 Standby 2 commands compared with R2

R1 has priority 90 whereas R2 has priority 95, so R2 wins!

On R2 you are tracking 1 (say that interface was to go down) HSRP process would decrement the priority by 10 so all in all R2 will have a priority of 85 - since preempt is enabled then R1 would take over because of the priority of 90. Same vice versa

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

standby 2 ip 192.168.182.1

standby 2 priority 90

standby 2 preempt

standby 2 track 1 decrement 10

R2

interface GigabitEthernet0/0

description Inside Interface

standby 2 ip 192.168.182.1

standby 2 priority 95

standby 2 preempt

standby 2 track 1 decrement 10

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

I would configure your R1 and R2 like this:

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

ip address 158.112.127.225 255.255.255.240 secondary

ip address 192.168.181.3 255.255.255.0 secondary

ip address 192.168.180.3 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 100               Default value

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 100               Default value

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 100

media-type rj45

no mop enabled

R2

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.180.2 255.255.255.0 secondary

ip address 192.168.181.2 255.255.255.0 secondary

ip address 192.168.182.2 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 95

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority 95

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 1000

media-type rj45

no mop enabled

This would mean that R1 will be the active gateway because of the priority 100 (highest wins)

Only until the tracked object goes 'down' (all based on the status of the object).

The priority on R1 will then be 100 - 10 = 90.

Since preempt is enabled R2 will win since it has 95. This is then the active gateway.

In this case you may not need the track command under R2 since it wont be active all the time.

When R1 recovers and the tracked item is back 'up' then everything goes back to normal.

R1 then has the original priority of 100, and becomes the active gateway once again.

Or the otherway round with R2 being active. Or even R1 being active for one of the groups and R2 being active for the other.

Hope this helps

Please rate useful posts & remember to mark any solved questions as answered. Thank you.

Thanks for the help. I actually just took all of the network over from the previous person that left, so I'm a little bogged down in all of it. I think part of my issue was that he told me that R2 was the primary, so I was trying to figure out how that was possible rather that just looking at the facts. I really appreciate the help.

Santosh Shetty
Level 1
Level 1

Default priority for HSRP = 100, device with highest ip is preferred.

So as per above configuration only R2 will forward the traffic.

Track 1 object is configured on you device. To know more you can issue command # sh track 1

If tracked object result true > hsrp priority will remain same

If tracked object result false > hsrp priority will be decremented by 10

Praveen AR
Level 1
Level 1

Hi,

I would suggest you to  make better redundancy solution using MHSRP

R1 Active gateway for group 2 and R2  standby for group 2

R2 Active gateway  for group 3 and R1 standby for group 3.

R1

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.182.3 255.255.255.0 secondary

ip address 158.112.127.225 255.255.255.240 secondary

ip address 192.168.181.3 255.255.255.0 secondary

ip address 192.168.180.3 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 100

standby 2 preempt

standby 2 track 1 decrement 10

standby 3 ip 192.168.180.1

standby 3 priority  95

duplex full

speed 100

media-type rj45

no mop enabled

R2

interface GigabitEthernet0/0

description Inside Interface

ip address 192.168.180.2 255.255.255.0 secondary

ip address 192.168.181.2 255.255.255.0 secondary

ip address 192.168.182.2 255.255.255.0

ip flow ingress

standby 2 ip 192.168.182.1

standby 2 priority 95

standby 3 ip 192.168.180.1

standby 3 priority 100

standby 3 preempt

standby 3 track 1 decrement 10

duplex full

speed 1000