From: Jeff K. (jeffbk@xxxxxxxxxxxxx)
Date: Wed Jun 06 2001 - 23:51:54 GMT-3
The default track decrement is 10, so when serial 1 fails on R1, the
priorities are equal. Since E0 on R1 is still up, there is no reason for R2
to take over - but it wouldn't take over anyway (even with a track of 11 or
more in this case) unless E0 on R1 went down since you don't have the
preempt statement on R2. Right now, when the R1 serial fails and its
priority is less, R1 will remain active. This is what the preempt statement
does -- it allows the router to immediately take over when it has higher
priority than the other. Once R1's serial comes back up, it's priority will
go back to 100 (as in your config) and the preempt statement you have
configured already will allow R1 to take over from R2. If you didn't have
that preempt, R2 would remain active even though R1 had higher priority.
Here is an easy way to test this. Shut the Ethernet interfaces on R1 and
R2. Configure R2, for example, with a priority of 90 for HSRP. No shut the
interface and do a 'sh stand brief' until you see it is active since it is
the only interface up. Configure R1 for HSRP in the same group with default
priority of 100. Do a 'sh stand brief' until it leaves the Speak state and
you'll see R1 is standby, R2 active. Do a standby preempt on R1 and it will
take over. If you bring both R1 and R2 up before they finish 'Listen' and
'Speak,' then the higher priority will be active.
Here is an article on CCO that explains this pretty well:
http://www.cisco.com/warp/public/619/6.html
HTH,
-Jeff
----- Original Message -----
From: "Jeongwoo Park" <jpark@wams.com>
To: "Ccielab@Groupstudy. Com" <ccielab@groupstudy.com>
Sent: Wednesday, June 06, 2001 8:39 PM
Subject: HSRP Track Serial interface
> Hi all
> I configured stand 1 track s0 on router r1.
> I expected r1 to fail over to r2 when I plugged out dte cable from S0 on
R1.
> Didn't work !!!!
> what is missing in my config?
>
>
> R1-------------ethernet----/R2
> | /
> | serial
> | /
> |serial /
> | /
> | /
> | /
> TermServer
>
> r1:
> hostname r1
> !
> !
> no ip domain-lookup
> !
> !
> interface Ethernet0
> ip address 10.10.1.1 255.255.255.0
> no ip redirects
> standby 1 priority 100
> standby 1 preempt
> standby 1 ip 10.10.1.3
> standby 1 track Serial0
> !
> interface Serial0
> ip address 172.16.1.2 255.255.255.0
> no ip mroute-cache
> !
> interface Serial1
> no ip address
> shutdown
> !
> ip classless
> !
> !
> line con 0
> line aux 0
> line vty 0 4
> login
> !
> end
>
> --------------------------------------------------------------
> r2:
> hostname r2
> !
> !
> ip subnet-zero
> no ip domain-lookup
> !
> !
> !
> interface Ethernet0
> ip address 10.10.1.2 255.255.255.0
> no ip redirects
> no ip directed-broadcast
> standby 1 priority 90
> standby 1 ip 10.10.1.3
> !
> interface Serial0
> ip address 172.16.2.2 255.255.255.0
> no ip directed-broadcast
> no ip mroute-cache
> !
> interface Serial1
> no ip address
> no ip directed-broadcast
> shutdown
> !
> interface TokenRing0
> no ip address
> no ip directed-broadcast
> shutdown
> !
> ip nat translation timeout never
> ip nat translation tcp-timeout never
> ip nat translation udp-timeout never
> ip nat translation finrst-timeout never
> ip nat translation syn-timeout never
> ip nat translation dns-timeout never
> ip nat translation icmp-timeout never
> ip classless
> !
> !
> line con 0
> transport input none
> line aux 0
> line vty 0 4
> login
> !
> end
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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