- Configuring GLBP
- HSRP for IPv6
- Configuring HSRP
- HSRP: Global IPv6 Address
- FHRP—HSRP BFD Peering
- HSRP Version 2
- FHRP - HSRP Group Shutdown
- FHRP - HSRP Multiple Group Optimization
- HSRP - ISSU
- SSO HSRP
- HSRP MD5 Authentication
- HSRP Support for ICMP Redirects
- HSRP Support for MPLS VPNs
- Configuring IRDP
- Configuring VRRP
- VRRPv3 Protocol Support
- VRRPv3: Object Tracking Integration
- Virtual Router Redundancy Service
Contents
- FHRP - HSRP Multiple Group Optimization
- Finding Feature Information
- Information About FHRP - Multiple Group Optimization
- HSRP Multiple Group Optimization
- How to configure FHRP - Multiple Group Optimization
- Configuring Multiple HSRP Groups for Load Balancing
- Improving CPU and Network Performance with HSRP Multiple Group Optimization
- Configuration Examples for FHRP - Multiple Group Optimization
- Example: Configuring Multiple HSRP Groups for Load Balancing
- Example: Improving CPU and Network Performance with HSRP Multiple Group Optimization
- Additional References
- Feature Information for FHRP - HSRP Multiple Group Optimization
FHRP - HSRP Multiple Group Optimization
- Finding Feature Information
- Information About FHRP - Multiple Group Optimization
- How to configure FHRP - Multiple Group Optimization
- Configuration Examples for FHRP - Multiple Group Optimization
- Additional References
- Feature Information for FHRP - HSRP Multiple Group Optimization
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About FHRP - Multiple Group Optimization
HSRP Multiple Group Optimization
The configuration of many hundreds of subinterfaces on the same physical interface, with each subinterface having its own HSRP group, can cause the processes of negotiation and maintenance of multiple HSRP groups to have a detrimental impact on network traffic and CPU utilization.
Only one HSRP group is required on a physical interface for the purposes of electing active and standby devices. This group is known as the master group. Other HSRP groups may be created on each subinterface and linked to the master group via the group name. These linked HSRP groups are known as client or slave groups.
The HSRP group state of the client groups follows that of the master group. Client groups do not participate in any sort of device election mechanism.
Client groups send periodic messages in order to refresh their virtual MAC addresses in switches and learning bridges. The refresh message may be sent at a much lower frequency compared with the protocol election messages sent by the master group.
How to configure FHRP - Multiple Group Optimization
- Configuring Multiple HSRP Groups for Load Balancing
- Improving CPU and Network Performance with HSRP Multiple Group Optimization
Configuring Multiple HSRP Groups for Load Balancing
Perform this task to configure multiple HSRP groups for load balancing.
Multiple HSRP groups enable redundancy and load-sharing within networks and allow redundant devices to be more fully utilized. A device actively forwarding traffic for one HSRP group can be in standby or in the listen state for another group.
If two devices are used, then Device A would be configured as active for group 1 and standby for group 2. Device B would be standby for group 1 and active for group 2. Fifty percent of the hosts on the LAN would be configured with the virtual IP address of group 1 and the remaining hosts would be configured with the virtual IP address of group 2. See the Example: Multiple HSRP for Load Balancing section for a diagram and configuration example.
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
ip
address
ip-address
mask [secondary]
5.
standby [group-number]
priority
priority
6.
standby [group-number]
preempt [delay {minimum |
reload |
sync}
delay]
7.
standby [group-number]
ip [ip-address]
secondary]
8. On the same device, repeat Steps 5 through 7 to configure the device attributes for different standby groups.
9.
exit
10. Repeat Steps 3 through 9 on another device.
DETAILED STEPS
Improving CPU and Network Performance with HSRP Multiple Group Optimization
Perform this task to configure multiple HSRP client groups.
The standby follow command configures an HSRP group to become a slave of another HSRP group.
HSRP client groups follow the master HSRP with a slight, random delay so that all client groups do not change at the same time.
Use the standby mac-refresh seconds command to directly change the HSRP client group refresh interval. The default interval is 10 seconds and can be configured to as much as 255 seconds.
Configure the HSRP master group using the steps in the Configuring Multiple HSRP Groups for Load Balancing section.
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
ip
address
ip-address
mask [secondary]
5.
standby
mac-refresh
seconds
6.
standby
group-number
follow
group-name
7.
exit
8. Repeat Steps 3 through 6 to configure additional HSRP client groups.
DETAILED STEPS
Configuration Examples for FHRP - Multiple Group Optimization
- Example: Configuring Multiple HSRP Groups for Load Balancing
- Example: Improving CPU and Network Performance with HSRP Multiple Group Optimization
Example: Configuring Multiple HSRP Groups for Load Balancing
You can use HSRP or multiple HSRP groups when you configure load sharing. In the figure below, half of the clients are configured for Router A, and half of the clients are configured for Router B. Together, the configuration for Routers A and B establish two Hot Standby groups. For group 1, Router A is the default active router because it has the assigned highest priority, and Router B is the standby router. For group 2, Router B is the default active router because it has the assigned highest priority, and Router A is the standby router. During normal operation, the two routers share the IP traffic load. When either router becomes unavailable, the other router becomes active and assumes the packet-transfer functions of the router that is unavailable. The standby preempt interface configuration command is necessary so that if a router goes down and then comes back up, preemption occurs and restores load sharing.
The following example shows Router A configured as the active router for group 1 with a priority of 110 and Router B configured as the active router for group 2 with a priority of 110. The default priority level is 100. Group 1 uses a virtual IP address of 10.0.0.3 and Group 2 uses a virtual IP address of 10.0.0.4.
Router A Configuration
Router(config)# hostname RouterA ! Router(config)# interface GigabitEthernet 0/0/0 Router(config-if)# ip address 10.0.0.1 255.255.255.0 Router(config-if)# standby 1 priority 110 Router(config-if)# standby 1 preempt Router(config-if)# standby 1 ip 10.0.0.3 Router(config-if)# standby 2 preempt Router(config-if)# standby 2 ip 10.0.0.4
Router B Configuration
Router(config)# hostname RouterB ! Router(config)# interface GigabitEthernet 0/0/0 Router(config-if)# ip address 10.0.0.2 255.255.255.0 Router(config-if)# standby 1 preempt Router(config-if)# standby 1 ip 10.0.0.3 Router(config-if)# standby 2 priority 110 Router(config-if)# standby 2 preempt Router(config-if)# standby 2 ip 10.0.0.4
Example: Improving CPU and Network Performance with HSRP Multiple Group Optimization
The following example shows how to configure an HSRP client and master group:
Device(config)# interface GigabitEthernet 0/0/0 Device(config-if)# no shutdown Device(config-if)# standby mac-refresh 30 ! Client Hello message interval ! Device(config)# interface GigabitEthernet 0/0/1 Device(config-if)# no shutdown Device(config-if)# ip vrf forwarding VRF2 Device(config-if)# ip address 10.0.0.100 255.255.0.0 Device(config-if)# standby 1 ip 10.0.0.254 Device(config-if)# standby 1 priority 110 Device(config-if)# standby 1 preempt Device(config-if)# standby 1 name HSRP1 !Server group ! Device(config)# interface GigabitEthernet 0/0/2 Device(config-if)# no shutdown Device(config-if)# ip vrf forwarding VRF3 Device(config-if)# ip address 10.0.0.100 255.255.0.0 Device(config-if)# standby 2 ip 10.0.0.254 Device(config-if)# standby 2 follow HSRP1 ! Client group ! Device(config)# interface GigabitEthernet 0/0/3 Device(config-if)# no shutdown Device(config-if)# ip vrf forwarding VRF4 Device(config-if)# ip address 10.0.0.100 255.255.0.0 Device(config-if)# standby 2 ip 10.0.0.254 Device(config-if)# standby 2 follow HSRP1 ! Client group
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
HSRP commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples |
Cisco IOS First Hop redundancy Protocols Command Reference |
|
HSRP for IPv6 |
“HSRP for IPv6” module |
|
Troubleshooting HSRP |
Standards
|
Standards |
Title |
|---|---|
|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
-- |
MIBs
|
MIBs |
MIBs Link |
|---|---|
|
CISCO-HSRP-MIB CISCO-HSRP-EXT-MIB |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
|
RFCs |
Title |
|---|---|
|
RFC 792 |
Internet Control Message Protocol |
|
RFC 1828 |
IP Authentication Using Keyed MD5 |
|
RFC 2281 |
Cisco Hot Standby Router Protocol |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for FHRP - HSRP Multiple Group Optimization
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
FHRP—HSRP Multiple Group Optimization |
12.4(6)T 12.2(33)SRB 12.2(33)SXI 12.2(50)SY 15.0(1)S 15.0(1)SY Cisco IOS XE Release 2.1 |
FHRP—HSRP Multiple Group Optimization feature improves the negotiation and maintenance of multiple HSRP groups configured on a subinterface. Only one HSRP group is required on a physical interface for the purposes of electing active and standby devices. This group is known as the master group. Other HSRP groups may be created on each subinterface and linked to the master group via the group name. These linked HSRP groups are known as client or slave groups. The following commands were introduced or modified by this feature: standby follow, show standby. |