Unicast Routing Configuration Guide, Cisco DCNM for LAN, Release 5.x
Configuring HSRP
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Configuring HSRP

Table Of Contents

Configuring HSRP

Information About HSRP

HSRP Overview

HSRP for IPv4

HSRP for IPv6

HSRP IPv6 Addresses

HSRP Versions

HSRP Authentication

HSRP Messages

HSRP Load Sharing

Object Tracking and HSRP

High Availability

Licensing Requirements for HSRP

Prerequisites for HSRP

Default Settings

Platform Support

Configuring HSRP

Configuring the HSRP Version

Configuring an HSRP Group for IPv4

Configuring an HSRP Group for IPv6

Configuring the HSRP Virtual MAC Address

Authenticating HSRP

Configuring Preemption

Configuring HSRP Object Tracking

Configuring the HSRP Priority

Customizing HSRP

Field Descriptions for HSRP

HSRP: Group Details Tab: Group Details Section

HSRP: Group Details Tab: Authentication, Router Preemption Section

HSRP: Group Details Tab: Timers Section

HSRP: Group Details Tab: Object Tracking Section

HSRP: Interface Settings Tab

Additional References

Related Documents

MIBs

Feature History for HSRP


Configuring HSRP


This chapter describes how to configure the Hot Standby Router Protocol (HSRP) on the Data Center Network Manager (DCNM).

This chapter includes the following sections:

Information About HSRP

Licensing Requirements for HSRP

Prerequisites for HSRP

Default Settings

Platform Support

Configuring HSRP

Field Descriptions for HSRP

Additional References

Feature History for HSRP

Information About HSRP

HSRP is a first-hop redundancy protocol (FHRP) that allows a transparent failover of the first-hop IP router. HSRP provides first-hop routing redundancy for IP hosts on Ethernet networks configured with a default router IP address. You use HSRP in a group of routers for selecting an active router and a standby router. In a group of routers, the active router is the router that routes packets; the standby router is the router that takes over when the active router fails or when preset conditions are met.

Many host implementations do not support any dynamic router discovery mechanisms but can be configured with a default router. Running a dynamic router discovery mechanism on every host is not feasible for a number of reasons, including administrative overhead, processing overhead, and security issues. HSRP provides failover services to these hosts.

This section includes the following topics:

HSRP Overview

HSRP for IPv4

HSRP Versions

HSRP Authentication

HSRP Messages

HSRP Load Sharing

Object Tracking and HSRP

High Availability

HSRP Overview

When you use HSRP, you configure the HSRP virtual IP address as the host's default router (instead of the IP address of the actual router). The virtual IP address is an IPv4 or IPv6 address that is shared among a group of routers that run HSRP.

When you configure HSRP on a network segment, you provide a virtual MAC address and a virtual IP address for the HSRP group. You configure the same virtual address on each HSRP-enabled interface in the group. You also configure a unique IP address and MAC address on each interface that acts as the real address. HSRP selects one of these interfaces to be the active router. The active router receives and routes packets destined for the virtual MAC address of the group.

HSRP detects when the designated active router fails. At that point, a selected standby router assumes control of the virtual MAC and IP addresses of the HSRP group. HSRP also selects a new standby router at that time.

HSRP uses a priority mechanism to determine which HSRP-configured interface becomes the default active router. To configure an interface as the active router, you assign it with a priority that is higher than the priority of all the other HSRP-configured interfaces in the group. The default priority is 100, so if you configure just one interface with a higher priority, that interface becomes the default active router.

Interfaces that run HSRP send and receive multicast User Datagram Protocol (UDP)-based hello messages to detect a failure and to designate active and standby routers. When the active router fails to send a hello message within a configurable period of time, the standby router with the highest priority becomes the active router. The transition of packet forwarding functions between the active and standby router is completely transparent to all hosts on the network.

You can configure multiple HSRP groups on an interface.

Figure 5-1 shows a network configured for HSRP. By sharing a virtual MAC address and a virtual IP address, two or more interfaces can act as a single virtual router.

Figure 5-1 HSRP Topology With Two Enabled Routers

The virtual router does not physically exist but represents the common default router for interfaces that are configured to provide backup to each other. You do not need to configure the hosts on the LAN with the IP address of the active router. Instead, you configure them with the IP address (virtual IP address) of the virtual router as their default router. If the active router fails to send a hello message within the configurable period of time, the standby router takes over, responds to the virtual addresses, and becomes the active router, assuming the active router duties. From the host perspective, the virtual router remains the same.


Note Packets received on a routed port destined for the HSRP virtual IP address will terminate on the local router, regardless of whether that router is the active HSRP router or the standby HSRP router. This includes ping and Telnet traffic. Packets received on a Layer 2 (VLAN) interface destined for the HSRP virtual IP address will terminate on the active router.


HSRP for IPv4

HSRP routers communicate with each other by exchanging HSRP hello packets. These packets are sent to the destination IP multicast address 224.0.0.2 (reserved multicast address used to communicate to all routers) on UDP port 1985. The active router sources hello packets from its configured IP address and the HSRP virtual MAC address while the standby router sources hellos from its configured IP address and the interface MAC address, which may or may not be the burned-in address (BIA). The BIA is the last six bytes of the MAC address that is assigned by the manufacturer of the network interface card (NIC).

Because hosts are configured with their default router as the HSRP virtual IP address, hosts must communicate with the MAC address associated with the HSRP virtual IP address. This MAC address is a virtual MAC address, 0000.0C07.ACxy, where xy is the HSRP group number in hexadecimal based on the respective interface. For example, HSRP group 1 uses the HSRP virtual MAC address of 0000.0C07.AC01. Hosts on the adjoining LAN segment use the normal Address Resolution Protocol (ARP) process to resolve the associated MAC addresses.

HSRP version 2 uses the new IP multicast address 224.0.0.102 to send hello packets instead of the multicast address of 224.0.0.2, which is used by version 1. HSRP version 2 permits an expanded group number range of 0 to 4095 and uses a new MAC address range of 0000.0C9F.F000 to 0000.0C9F.FFFF.

HSRP for IPv6

IPv6 hosts learn of available IPv6 routers through IPv6 neighbor discovery (ND) router advertisement (RA) messages. These messages are multicast periodically, or may be solicited by hosts, but the time delay for detecting when a default route is down may be 30 seconds or more. HSRP for IPv6 provides a much faster switchover to an alternate default router than the IPv6 ND protocol provides, less than a second if the milliseconds timers are used. HSRP for IPv6 provides a virtual first hop for IPv6 hosts.

When you configure an IPv6 interface for HSRP, the periodic RAs for the interface link-local address stop after IPv6 ND sends a final RA with a router lifetime of zero. No restrictions occur for the interface IPv6 link-local address. Other protocols continue to receive and send packets to this address.

IPv6 ND sends periodic RAs for the HSRP virtual IPv6 link-local address when the HSRP group is active. These RAs stop after a final RA is sent with a router lifetime of 0 when the HSRP group leaves the active state. HSRP uses the virtual MAC address for active HSRP group messages only (hello, coup, and redesign).

HSRP for IPv6 uses the following parameters:

HSRP version 2

UDP port 2029

Virtual MAC address range from 0005.73A0.0000 through 0005.73A0.0FFF

Multicast link-local IP destination address of FF02::66

Hop limit set to 255

HSRP IPv6 Addresses

An HSRP IPv6 group has a virtual MAC address that is derived from the HSRP group number and a virtual IPv6 link-local address that is derived, by default, from the HSRP virtual MAC address. The default virtual MAC address for an HSRP IPv6 group will always be used to form the virtual IPv6 link-local address, regardless of the actual virtual MAC address used by the group.

Table 5-1 shows the MAC and IP addresses used for IPv6 neighbor discovery packets and HSRP packets.

Table 5-1 HSRP and IPv6 ND Addresses 

Packet
MAC Source Address
IPv6 Source Address
IPv6 Destination Address
Link-layer Address Option

Neighbor solicitation (NS)

Interface MAC address

Interface IPv6 address

Interface MAC address

Router solicitation (RS)

Interface MAC address

Interface IPv6 address

Interface MAC address

Neighbor advertisement (NA)

Interface MAC address

Interface IPv6 address

Virtual IPv6 address

HSRP virtual MAC address

Route advertisement (RA)

Interface MAC address

Virtual IPv6 address

HSRP virtual MAC address

HSRP (inactive)

Interface MAC address

Interface IPv6 address

HSRP (active)

Virtual MAC address

Interface IPv6 address


HSRP does not add IPv6 link-local addresses to the Unicast Routing Information Base (URIB). There are also no secondary virtual IP addresses for link-local addresses.

For global unicast addresses, HSRP will add the virtual IPv6 address to the URIB and IPv6 but will not register the virtual IPv6 addresses to ICMPv6. ICMPv6 redirects are not supported for HSRP IPv6 groups.

HSRP Versions

Cisco NX-OS supports HSRP version 1 by default. You can configure an interface to use HSRP version 2.

HSRP version 2 has the following enhancements to HSRP version 1:

Expands the group number range. HSRP version 1 supports group numbers from 0 to 255. HSRP version 2 supports group numbers from 0 to 4095.

For IPv4, uses the IPv4 multicast address 224.0.0.102 or the IPv6 multicast address FF02::66 to send hello packets instead of the multicast address of 224.0.0.2, which is used by HSRP version 1.

Uses the MAC address range from 0000.0C9F.F000 to 0000.0C9F.FFFF for IPv4 and 0005.73A0.0000 through 0005.73A0.0FFF for IPv6 addresses. HSRP version 1 uses the MAC address range 0000.0C07.AC00 to 0000.0C07.ACFF.

Adds support for MD5 authentication.

When you change the HSRP version, Cisco NX-OS reinitializes the group because it now has a new virtual MAC address.

HSRP version 2 has a different packet format than HSRP version 1. The packet format uses a type-length-value (TLV) format. HSRP version 2 packets received by an HSRP version 1 router are ignored.

HSRP Authentication

HSRP message digest 5 (MD5) algorithm authentication protects against HSRP-spoofing software and uses the industry-standard MD5 algorithm for improved reliability and security. HSRP includes the IPv4 or IPv6 address in the authentication TLVs.

HSRP Messages

Routers that are configured with HSRP exchange the following three types of multicast messages:

Hello—The hello message conveys the HSRP priority and state information of the router to other HSRP routers.

Coup—When a standby router wants to assume the function of the active router, it sends a coup message.

Resign—A router that is the active router sends this message when it is about to shut down or when a router that has a higher priority sends a hello or coup message.

HSRP Load Sharing

HSRP allows you to configure multiple groups on an interface. You can configure two overlapping IPv4 HSRP groups to load share traffic from the connected hosts while providing the default router redundancy expected from HSRP. Figure 5-2 shows an example of a load-sharing HSRP IPv4 configuration.

Figure 5-2 HSRP Load Sharing

Figure 5-2 shows two routers A and B and two HSRP groups. Router A is the active router for group A but is the standby router for group B. Similarly, router B is the active router for group B and the standby router for group A. If both routers remain active, HSRP load balances the traffic from the hosts across both routers. If either router fails, the remaining router continues to process traffic for both hosts.


Note HSRP for IPv6 load balances by default. If there are two HSRP IPv6 groups on the subnet, then hosts will learn of both from their router advertisements and choose to use one so that the load is shared between the advertised routers.


Object Tracking and HSRP

You can use object tracking to modify the priority of an HSRP interface based on the operational state of another interface. Object tracking allows you to route to a standby router if the interface to the main network fails.

Two objects that you can track are the line protocol state of an interface or the reachability of an IP route. If the specified object goes down, Cisco NX-OS reduces the HSRP priority by the configured amount. For more information, see the "Configuring HSRP Object Tracking" section.


Note You should configure HSRP on the primary vPC peer device as active and HSRP on the vPC secondary device as standby.


High Availability

HSRP supports stateful restarts and stateful switchovers. A stateful restart occurs when the HSRP process fails and is restarted. A stateful switchover occurs when the active supervisor switches to the standby supervisor. Cisco NX-OS applies the run-time configuration after the switchover.

Licensing Requirements for HSRP

The following table shows the licensing requirements for this feature:

Product
License Requirement

Cisco DCNM

HSRP requires the Enterprise LAN license. Any feature not included in a license package is bundled with the Cisco DCNM and is provided at no charge to you. For a complete explanation of the Cisco DCNM licensing scheme, see the Cisco DCNM Installation and Licensing Guide, Release 5.x.

Cisco NX-OS

HSRP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For an explanation of the Cisco NX-OS licensing scheme for your platform, see the licensing guide for your platform.


Prerequisites for HSRP

The following prerequisites are required for using this feature on Cisco DCNM. For a full list of feature-specific prerequisites, see the platform-specific documentation.

HSRP has the following prerequisites:

System-message logging levels for the HSRP feature must meet or exceed Cisco DCNM requirements. During device discovery, Cisco DCNM detects inadequate logging levels and raises them to the minimum requirements. Cisco Nexus 7000 Series switches that run Cisco NX-OS Release 4.0 are an exception. For Cisco NX-OS Release 4.0, prior to device discovery, use the command-line interface to configure logging levels to meet or exceed Cisco DCNM requirements. For more information, see the Cisco DCNM Fundamentals Guide, Release 5.x.

Default Settings

Table 5-2 lists the default settings for HSRP parameters.

Table 5-2 Default HSRP Parameters 

Parameters
Default

HSRP

Disabled

Authentication

Enabled as text for version 1, with cisco as the password

HSRP version

Version 1

Preemption

Disabled

Priority

100

virtual MAC address

Derived from HSRP group number


Platform Support

The following platform supports this feature. For platform-specific information, including guidelines and limitations, system defaults, and configuration limits, see the corresponding documentation.

Platform
Documentation

Cisco Nexus 7000 Series switches

Cisco Nexus 7000 Series Switches Documentation


Configuring HSRP

You can access HSRP from the Routing feature selection.

For more information about the Cisco Data Center Network Manager features, see the Cisco DCNM Fundamentals Guide, Release 5.x.

This section includes the following topics:

Configuring the HSRP Version

Configuring an HSRP Group for IPv4

Configuring an HSRP Group for IPv6

Configuring the HSRP Virtual MAC Address

Authenticating HSRP

Configuring Preemption

Configuring HSRP Object Tracking

Configuring the HSRP Priority

Customizing HSRP

Configuring the HSRP Version

You can configure the HSRP version. If you change the version for existing groups, Cisco NX-OS reinitializes HSRP for those groups because the virtual MAC address changes. The HSRP version applies to all groups on the interface.


Note IPv6 HSRP groups must be configured as HSRP version 2.


DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Interface Settings tab.

The Interface Settings tab appears.

Step 5 From the Interface Settings tab, in the HSRP Version field, enter 1 for HSRP version 1 or enter 2 for HSRP version 2.

Step 6 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring an HSRP Group for IPv4

You can configure an HSRP group on an IPv4 interface and configure the virtual IP address and virtual MAC address for the HSRP group.

BEFORE YOU BEGIN

Cisco NX-OS enables an HSRP group once you configure the virtual IP address on any member interface in the group. You should configure HSRP attributes such as authentication, timers, and priority before you enable the HSRP group.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

Step 3 Right-click and choose New IPv4 GroupSetting.

Step 4 From the Interface drop-down list, select the interface or group of interfaces that you want to configure an HSRP group on.

Step 5 From the Group ID field, enter the group number for this group.

The range is from 0 to 255.

Step 6 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 7 From the Group Details tab, expand the Group Details section.

The basic group information appears in the Details pane.

Step 8 (Optional) From the Group Name field, enter a name for this HSRP group member.

Step 9 (Optional) From the Virtual IP Address Settings Area, check Learn Virtual IP from Members of Group to learn the virtual IP address from another HSRP group member.

Step 10 (Optional) From the Virtual IP Address Settings Area, in the Virtual IP Address field, enter an IPv4 address.

Step 11 (Optional) From the Virtual IP Address Settings Area, in the Secondary IP Address field, enter an IPv4 address for the secondary IP address.

Step 12 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring an HSRP Group for IPv6

You can configure an HSRP group on an IPv6 interface and configure the virtual MAC address for the HSRP group.

When you configure an HSRP group for IPv6, HSRP generates a link-local address from the link-local prefix. HSRP also generates a modified EUI-64 format interface identifier in which the EUI-64 interface identifier is created from the relevant HSRP virtual MAC address.

There are no HSRP IPv6 secondary addresses.

BEFORE YOU BEGIN

Ensure that you have enabled HSRP version 2 on the interface that you want to configure an IPv6 HSRP group on.

Ensure that you have configured HSRP attributes such as authentication, timers, and priority before you enable the HSRP group.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

Step 3 Right-click and choose New IPv6 GroupSetting.

Step 4 From the Interface drop-down list, select the interface or group of interfaces that you want to configure an HSRP group on.

Step 5 From the Group ID field, enter the group number for this group.

Step 6 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 7 From the Group Details tab, expand the Interfaces section.

The HSRP interface information appears in the Details pane.

Step 8 From the HSRP Version field, enter 2 for HSRP version 2.

Step 9 From the Group Details tab, expand the Group Details section.

The basic group information appears in the Details pane.

Step 10 (Optional) From the Group Name field, enter a name for this HSRP group member.

Step 11 (Optional) From the Virtual IP Address Settings Area, check Autoconfigure IP address to configure the virtual IPv6 address from the link-local address and the HSRP virtual MAC address.

Step 12 (Optional) From the Virtual IP Address Settings Area, check Learn Virtual IP from Members of Group to learn the virtual IP address from another HSRP group member.

Step 13 (Optional) From the Virtual IP Address Settings Area, in the Virtual IPv6 Address field, enter an IPv6 address.

Step 14 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring the HSRP Virtual MAC Address

You can override the default virtual MAC address that HSRP derives from the configured group number.


Note You must configure the same virtual MAC address on both vPC peers of a vPC link.


DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Group Details section.

The basic group information appears in the Details pane.

Step 6 From the Virtual MAC Address field, enter the virtual MAC address.

The string uses the standard MAC address format (xxxx.xxxx.xxxx).

Step 7 From the menu bar, choose File > Deploy to apply your changes to the device.


You can configure HSRP to use the burned-in MAC address as the virtual MAC address on an interface.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Interface Settings tab.

The Interface Settings tab appears.

Step 5 From the Interface Settings tab, check Use Burned In Address (use-bia).

Step 6 (Optional) To use the burned-in address for all groups, check Apply Use Burned In Address (use-bia) to all Groups.

Step 7 From the menu bar, choose File > Deploy to apply your changes to the device.


Authenticating HSRP

You can configure HSRP to authenticate the protocol using cleartext or MD5 digest authentication. MD5 authentication uses a key chain (see the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 5.x).

BEFORE YOU BEGIN

You must configure the same authentication and keys on all members of the HSRP group.

Ensure that you have created the key chain if you are using MD5 authentication.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Authentication, Router Preemption section.

The authentication information appears in the Details pane.

Step 6 From the Authentication area, from the Method drop-down list, choose the authentication method.

Step 7 (Optional) For text authentication, in the password field, enter the password string.

Step 8 (Optional) For MD5 authentication, choose either Key or Key Chain.

Step 9 (Optional) For the Key option, in the key field, enter the key string, time-out value, and check Encrypted for an encrypted key string.

Step 10 (Optional) For the Key Chain option, from the key chain drop-down list, choose the key chain that you want to use.

Step 11 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring Preemption

You can configure HSRP to preempt another active router based on the configured priority.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Authentication, Router Preemption section.

The authentication information appears in the Details pane.

Step 6 Check Router Preemption.

Step 7 From the Minimum Delay(sec) field, enter the minimum delay time.

Step 8 From the Sync Delay(sec) field, enter the sync delay time.

Step 9 From the Reload Delay(sec) field, enter the reload delay time.

Step 10 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring HSRP Object Tracking

You can configure an HSRP group to adjust its priority based on the availability of other interfaces or routes. The priority of a device can change dynamically if it has been configured for object tracking and the object that is being tracked goes down.

The tracking process periodically polls the tracked objects and notes any value change. The value change triggers HSRP to recalculate the priority. The HSRP interface with the higher priority becomes the active router if you configure the HSRP interface for preemption. For more information on object tracking, see the "Configuring Preemption" section.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Object Tracking section.

The object tracking information appears in the Details pane.

Step 6 Right-click and choose Add Track Object.

Step 7 From the object ID drop-down list, choose the object ID that you want to use to modify the HSRP priority value with.

Step 8 In the Decrement field, enter the value that you want to decrement the HSRP priority with if the tracked object state goes down.

Step 9 From the menu bar, choose File > Deploy to apply your changes to the device.


Configuring the HSRP Priority

You can configure the HSRP priority on an interface. HSRP uses the priority to determine which HSRP group member acts as the active router. If you configure HSRP on a vPC-enabled interface, you can optionally configure the upper and lower threshold values to control when to fail over to the vPC trunk If the standby router priority falls below the lower threshold, HSRP sends all standby router traffic across the vPC trunk to forward through the active HSRP router. HSRP maintains this scenario until the standby HSRP router priority increases above the upper threshold.

For IPv6 HSRP groups, if all group members have the same priority, HSRP selects the active router based on the IPv6 link-local address.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure the HSRP priority on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure the HSRP priority on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Group Details section.

The basic group information appears in the Details pane.

Step 6 (Optional) From the Configured Priority field, enter the priority for this HSRP group member.

The range is from 1 to 255. The default is 100.

Step 7 (Optional) Check Forwarding Threshold and set the upper and lower threshold values used by vPC to determine when to fail over to the vPC trunk.

The range is from 1 to 255. The lower threshold default is 1. The upper threshold default is 100.

Step 8 From the menu bar, choose File > Deploy to apply your changes to the device.


Customizing HSRP

You can optionally customize the behavior of HSRP. Be aware that as soon as you enable an HSRP group by configuring a virtual IP address, that group is now operational. If you first enable an HSRP group before customizing HSRP, the router could take control over the group and become the active router before you finish customizing the feature. If you plan to customize HSRP, you should do so before you enable the HSRP group.

DETAILED STEPS


Step 1 From the Feature Selector pane, choose Routing > Gateway Redundancy > HSRP.

The available devices appear in the Summary pane.

Step 2 From the Summary pane, click the device that you want to configure HSRP on.

The system highlights the HSRP row in the Summary pane, and tabs update in the Details pane.

Step 3 From the highlighted Interface field, select the interface that you want to configure an HSRP group on from the drop-down list.

Step 4 From the Details pane, click the Group Details tab.

The Group Details tab appears.

Step 5 From the Group Details tab, expand the Timers section.

The HSRP timers information appears in the Details pane.

Step 6 From the Configured Timers area, in the Hello Time field, enter the hello time.

Step 7 Choose sec or msec from the drop-down list.

Step 8 From the Configured Timers area, in the Hold Time field, enter the hold time.

Step 9 Choose sec or msec from the drop-down list.

Step 10 From the menu bar, choose File > Deploy to apply your changes to the device.


Field Descriptions for HSRP

This section includes the following field descriptions for HSRP:

HSRP: Group Details Tab: Group Details Section

HSRP: Group Details Tab: Authentication, Router Preemption Section

HSRP: Group Details Tab: Timers Section

HSRP: Group Details Tab: Object Tracking Section

HSRP: Interface Settings Tab

HSRP: Group Details Tab: Group Details Section

Table 5-3 HSRP: Group Details: Group Details 

Field
Description
Router

Group ID

Display only. Group number for the HSRP group.

Group Name

Name of the HSRP group.

Configured Priority

Configured priority for the group.

Virtual MAC Address

MAC address of the virtual router.

Active Priority

Display only. Priority for the group.

Router State

Display only. State of the group.

State Change Count

Display only. Number of state changes for the group.

Last State Change

Display only. Time of the last state change for the group.

IP Address Settings

Autoconfigure IP address

Configures the virtual IPv6 address from the link-local address and the HSRP virtual MAC address.

Learn Virtual IP from Members of Group

Learns the virtual IPv4 or IPv6 address from other members of the HSRP group.

Virtual IP Address

IPv4 address of the virtual router.

Secondary IP Address

Secondary IPv4 address of the virtual router.

Forwarding Threshold

Forwarding Threshold

Enables threshold values for vPC.

Lower Threshold

Lower forwarding threshold value.

Upper Threshold

Upper forwarding threshold value.

Active Router

IP Address

Display only. IPv4 or IPv6 address of the active router.

Priority

Display only. Priority of the active router.

Standby Router

IP Address

Display only. IPv4 or IPv6 address of the standby router.

Priority

Display only. Priority of the standby router.


HSRP: Group Details Tab: Authentication, Router Preemption Section

Table 5-4 HSRP: Group Details: Authentication, Router Preemption  

Field
Description
Authentication

Method

Authentication method for this HSRP group.

Password

Password if text authentication is selected.

Key Chain

Key chain name if key-chain authentication is selected.

Key

Password if key-chain authentication is not selected.

Encrypted

Encrypts the password for this HSRP group.

Router Preemption

Router Preemption

Enables router preemption.

Minimum Delay

Minimum time that router preemption can be delayed.

Sync Delay

Maximum time to allow IP redundancy clients to prevent router preemption.

Reload Delay

Time after a router reload occurs before HSRP detects an interface up event.


HSRP: Group Details Tab: Timers Section

Table 5-5 HSRP: Group Details:Timers 

Field
Description
Active Timer Values

Hello Time

Display only. Hello time for this HSRP group.

Hold Time

Display only. Hold time for this HSRP group.

Configured Timer s

Hello Time

Hello time for this HSRP group.

Hold Time

Hold time for this HSRP group.

sec/msec

Unit of time for the configured timer.


HSRP: Group Details Tab: Object Tracking Section

Table 5-6 HSRP: Group Details: Object Tracking  

Field
Description

Track ID

Object tracking identifier.

Tracked Object

Display only. Name of the tracked object.

Decrement

Value to decrement the HSRP group priority if tracked object status is down.


HSRP: Interface Settings Tab

Table 5-7 HSRP:Interface Settings Tab 

Field
Description

HSRP Version

Version of HSRP for all groups on this interface.

Minimum Delay

Minimum time to delay HSRP group initialization after this interface comes up.

Reload Delay

Time to delay after a router reload occurs before HSRP detects this interface is up.

Use Burned In Address

Use the burned-in MAC address of this interface instead of the HSRP virtual MAC address.


Additional References

For additional information related to implementing HSRP, see the following sections:

Related Documents

MIBs

Related Documents

Related Topic
Document Title

Configuring the Gateway Load Balancing protocol

Chapter 4 "Configuring GLBP"

HSRP CLI commands

Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference

Configuring high availability

Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide, Release 5.x


MIBs

MIBs
MIBs Link

CISCO-HSRP-MIB

To locate and download MIBs, go to the following URL:

http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml


Feature History for HSRP

Table 5-8 lists the release history for this feature.

Table 5-8 Feature History for HSRP

Feature Name
Releases
Feature Information

IPv6

5.0(2)

Added support for IPv6.

DCNM support

4.1(2)

Added support for HSRP to DCNM.