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HSRP and Load Balancing

I have two routers (R1 and R2) in redundancy running HSRP (in the LAN segment) these routers connects to other

two routers (RA and RB, out of the LAN segment) each. So my question is if there is some command that can help me in

keeping track in RA and RB about the status of the interfaces running HSRP in R1 and R2??

Any help I'll be useful

Thanks!!

1 ACCEPTED SOLUTION

Accepted Solutions
Super Bronze

Re: HSRP and Load Balancing

Perhaps the easiest way for RA and RB to "know" of the LAN interface status of R1 and R2 is to run a dynamic routing protocol between the routers and advertise the LAN segment. (This has nothing to do with HSRP, which makes sense since HSRP provides a virtual gateway outbound but your question is tracking reachability from other outside routers, not local LAN hosts.)

Another way, if the platform is new enough, is to track the R1 and R2 LAN interface on RA and RB using IP SLA. This method, I recall, allows you to manipulate static routes on RA and RB pointing to R1 and R2. See http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html for some more information on this technique.

11 REPLIES

Re: HSRP and Load Balancing

i can see from ur topology u have two redundant uplinks from R1,R2

to both RA and RB

then the best way is to run HSRP on RA and RB and track the interfaces lets say the RA is the primary u need to track the RA interfaces connected to the internet, once it down HSRP can failover to RB and will be transperant to the other network

When an active router tracks serial 0 and the serial line goes down, how does the standby router know to become active?

A. When the state of a tracked interface changes to down, the active router decrements its priority. The standby router reads this value from the hello packet priority field, and becomes active if this value is lower than its own priority and the standby preempt is configured. You can configure by how much the router must decrement the priority. By default, it decrements its priority by ten.

and the following simple example similer to ur case but not same !!

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080093f2c.shtml

good luck

if helpful Rate

New Member

Re: HSRP and Load Balancing

Nice help, marwanshawi, thanks for your reply!!

hugs!

Re: HSRP and Load Balancing

u welcome :)

if helpful Rate please,

New Member

Re: HSRP and Load Balancing

Excuse me, marwanshawi, but my customer doesn't want to changes his scenario so HSRP needs to be running on R1 and R2 thus I still needing a command that tells me what I said before. Any help??

New Member

Re: HSRP and Load Balancing

interface tracking would work here under HSRP config under interfaces you want to track

New Member

Re: HSRP and Load Balancing

I don't think so, my friend, because on RA and RB HSRP is not running. Did you see the attached picture??

Thanks for your response, I really appreciate it.

New Member

Re: HSRP and Load Balancing

The standby track interface configuration command ties the router hot standby priority to the availability of its interfaces and is useful for tracking interfaces that are not configured for HSRP. When a tracked interface fails, the hot standby priority on the device on which tracking has been configured decreases by 10. If an interface is not tracked, its state changes do not affect the hot standby priority of the configured device. For each interface configured for hot standby, you can configure a separate list of interfaces to be tracked.

•The standby track interface-priority interface configuration command specifies how much to decrement the hot standby priority when a tracked interface goes down. When the interface comes back up, the priority is incremented by the same amount.

•When multiple tracked interfaces are down and interface-priority values have been configured, the configured priority decrements are cumulative. If tracked interfaces that were not configured with priority values fail, the default decrement is 10, and it is noncumulative.

•When routing is first enabled for the interface, it does not have a complete routing table. If it is configured to preempt, it becomes the active router, even though it is unable to provide adequate routing services. To solve this problem, configure a delay time to allow the router to update its routing table.

New Member

Re: HSRP and Load Balancing

Command

Purpose

Step 1

configure terminal

Enter global configuration mode.

Step 2

track object-number {interface interface-id {line-protocol | ip routing} | ip route ip-address/prefix-length {metric threshold | reachability} | list {boolean {and | or}} | {threshold {weight | percentage}}}

(Optional) Create a tracking list to track the configured state and enter tracking configuration mode.

Note Although visible in the command-line help, the rtr keyword is not supported.

•The object-number range is from 1 to 500.

•Enter interface interface-id to select an interface to track.

-Enter line-protocol to track the interface line protocol state.

-Enter ip routing to track the interface IP routing state.

•Enter ip route ip-address/prefix-length to track the state of an IP route.

-Enter metric threshold to track the threshold metric. The default up threshold is 254 and the default down threshold is 255.

-Enter reachability to track if the route is reachable.

•Enter list to track objects grouped in a list. Configure the list as described on the previous pages.

-For boolean, see the "Boolean Expression" section

-For threshold weight, see the "Weight Threshold" section

-For threshold percentage, see the "Percentage Threshold" section

Note Repeat this step for each interface to be tracked.

Step 3

exit

Return to global configuration mode.

Step 4

interface interface-id

Enter interface configuration mode.

Step 5

standby [group-number] ip [ip-address [secondary]]

Create (or enable) the HSRP group by using its number and virtual IP address.

•(Optional) group-number-The group number on the interface for which HSRP is being enabled. The range is 0 to 255; the default is 0. If there is only one HSRP group, you do not need to enter a group number.

•(Optional on all but one interface) ip-address-The virtual IP address of the hot standby router interface. You must enter the virtual IP address for at least one of the interfaces; it can be learned on the other interfaces.

•(Optional) secondary-The IP address is a secondary hot standby router interface. If this keyword is omitted, the configured address is the primary IP address.

Step 6

standby [group-number] track object-number [decrement [priority-decrement]]

Configure HSRP to track an object and change the hot standby priority based on the state of the object.

•(Optional) group-number-The group number to which the tracking applies.

•object-number-Number representing the object to be tracked. The range is from 1 to 500; the default is 1.

•(Optional) decrement priority-decrement-Amount by which the hot standby priority for the router is decremented (or incremented) when the tracked object goes down (or comes back up). The range is from 1 to 255; the default is 10.

Step 7

end

Return to privileged EXEC mode.

Step 8

show standby

Verify the standby router IP address and tracking states.

Step 9

copy running-config startup-config

(Optional) Save your entries in the configuration file.

New Member

Re: HSRP and Load Balancing

Nice Answer, my friend, I know how to configure HSRP and tracking interfaces and the result that this generates but tracking interfaces it makes aware the router that owns tracking interfaces and what I need is that RA and RB makes aware of the status of other interfaces in other routers (R1 and R2) as seen in the picture I attached.

Thanks for your reply!!

Super Bronze

Re: HSRP and Load Balancing

Perhaps the easiest way for RA and RB to "know" of the LAN interface status of R1 and R2 is to run a dynamic routing protocol between the routers and advertise the LAN segment. (This has nothing to do with HSRP, which makes sense since HSRP provides a virtual gateway outbound but your question is tracking reachability from other outside routers, not local LAN hosts.)

Another way, if the platform is new enough, is to track the R1 and R2 LAN interface on RA and RB using IP SLA. This method, I recall, allows you to manipulate static routes on RA and RB pointing to R1 and R2. See http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html for some more information on this technique.

New Member

Re: HSRP and Load Balancing

Thanks dude!! your help resolved my issue

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