HSRP no standby preempt

This is the preempt logic according to the book ICND2 OCG:

"If configured with no preemption (the default; no standby preempt), the local router becomes a standby router, even if it has a better (higher) priority."

However it's making no difference in my lab. For example, both routers are using version 2 with preemption disabled, if I set one router to use a higher priority than the other and bounce the interface it will take over as the active router when it comes back up.

The same thing happens with preemption enabled but that was expected. Has anyone else had a similar expierence? I take it I go by the book for the exam? I find it strange how the command is accpeted and appears in 'show' commands but it makes no different to the funcationality.

I'm using (C1841-ADVIPSERVICESK9-M) Version 15.1(2)T

Find more posts tagged with

Comments

Welly_59

Packet tracer, gns3 or real equipment?

WastedHat

Welly_59 wrote: »

Packet tracer, gns3 or real equipment?

Real equipment

TheNewITGuy

What is the output of show standby?

WastedHat

Heres what I'm getting. I did the first "show standby" at the same time on R1 and R2.

Then I changed R1's priority to 110 and bounced the interface, when it comes back up it takes over at the active router even though preemption is disabled on both routers.

Even if I leave the priority as default on both routers and bounce the interface on one of them it will take over as the active router when it comes back up. I think the funcationality isnt there or I'm missing something really obvious.

http://imgur.com/1RSfwYB

stand.jpg

hurricane1091

Packet Tracer is always buggy. I really don't like it.

WastedHat

hurricane1091 wrote: »

Packet Tracer is always buggy. I really don't like it.

This was on my physical routers. Two 1841's with IOS 15.

atippett

Can you give us more text from the book? I think it is meaning to say it will stay the standby router, until the interface is bounced. Correct me if I'm wrong, senior network guys.

hurricane1091

WastedHat wrote: »

This was on my physical routers. Two 1841's with IOS 15.

Ahh, I misread. I have never used those unfortunately, but they are older right? Seems odd.

Welly_59

i have just tried with packet tracer, gns3 and physical 2811's and i cannot get the same result as you.

I am getting the expected result on all

mikeybinec

Restart the routers. Just because one has a higher priority and it goes down, the backup is master/active unless you enable preemption. Also, IP addresses are the last attribute (highest) is deciding which is the master router. So give your first master router the higher IP address

WastedHat

atippett wrote: »

Can you give us more text from the book? I think it is meaning to say it will stay the standby router, until the interface is bounced. Correct me if I'm wrong, senior network guys.

This is the full description:

"…discovers an existing HSRP router in the subnet, and that router is already
acting as the active router:

A. If configured with no preemption (the default; no standby preempt),
the local router becomes a standby router, even if it has a better (higher)
priority.

B. If configured with preemption (standby preempt), the local router
checks its priority versus the active router; if the local router priority is
better (higher), the local router takes over (preempts) the existing active
router to become the new active HSRP router."

Welly_59 wrote: »

i have just tried with packet tracer, gns3 and physical 2811's and i cannot get the same result as you.

I am getting the expected result on all

Thanks for double checking, must be isolated to my lab. Were you using a switch between both routers? I'll need to check it out on GNS when I have time.

mikeybinec wrote: »

Restart the routers. Just because one has a higher priority and it goes down, the backup is master/active unless you enable preemption. Also, IP addresses are the last attribute (highest) is deciding which is the master router. So give your first master router the higher IP address

I just tried it again and preemption is still having no effect, I think it could be my IOS version. The higher IP works for me when both priorites are the same and both interfaces come up at the same time. Thanks.