# Hot Standby Router Protocol (HSRP) Configuration

Port > Configure > HSRP Configuration

The following information is displayed:

- Timeout for rows (cHsrpConfigTimeout)
- Group Number (cHsrpGrpNumber)
- Authentication String (cHsrpGrpAuth)
- Group Priority (cHsrpGrpPriority)
- Preempt (cHsrpGrpPreempt)
- Preempt Delay (cHsrpGrpPreemptDelay)
- Timers Configured (cHsrpGrpUseConfiguredTimers)

The following list specifies buttons in this dialog box, as well as their function:

- Click OK to continue.

- Click Apply to save the changes in the dialog box.

- Click Cancel to close the dialog box.

- With an entry selected, click Timers to launch the HSRP Group Timers dialog box.

- With an entry selected, click Status to launch the HSRP Group Status dialog box.

- Click Refresh to update the contents of the dialog box.

- Click Print to print the contents of the dialog box.

- Click Help to access online help.

Timeout for rows (cHsrpConfigTimeout)

Amount of time, in minutes, a row in cHsrpGrpTable can remain in a state other than "active" before being timed out.

Group Number (cHsrpGrpNumber)

This object, along with the ifIndex of a particular interface, uniquely identifies an HSRP group. The numbers 0,1 and 2 are the only valid group numbers for Token Ring interfaces. For other media types, valid group numbers range from 0 to 255.

There is no relationship between groups configured on different interfaces. The use of a group number on one interface does not preclude the use of the same group number on a different interface. More details can be found in RFC-2281.

Authentication String (cHsrpGrpAuth)

Unencrypted authentication string which is carried in all HSRP messages. An authentication string mismatch prevents a router interface from learning the designated IP address or HSRP timer values from other HSRP-enabled routers with the same group number.

The function of this object is not to supply any sort of security-like authentication. Rather, it is intended to provide a sanity check.

Group Priority (cHsrpGrpPriority)

Helps select the active and the standby routers. The router with the highest priority is selected as the active router. Priorities range from 0 to 255, where 0 is the lowest priority and 255 is the highest priority.

If two or more routers in a group have the same priority, the one with the highest IP address of the interface is the active router. 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.

A router with highest priority will only attempt to overthrow a lower priority active router if it is configured to preempt. But, if there is more than one router which is not active, the highest priority non-active router becomes the standby router.

Preempt (cHsrpGrpPreempt)

When the value of this object is "TRUE", it indicates that the current router will attempt to overthrow a lower priority active router and become the active router. When the value of this object is "FALSE", the current router will become the active router only if another router is not already active (or if an active router fails).

Preempt Delay (cHsrpGrpPreemptDelay)

Time difference between a router power up and the time it can actually start preempting the current active router.

When a router first comes up, it does not have a complete routing table. If the router is configured to preempt, then it will become the Active router, but it will not be able to provide adequate routing services. The solution to this problem is to allow for a configurable delay before the router actually preempts the currently active router.

Timers Configured (cHsrpGrpUseConfiguredTimers)

HSRP routers learn a group's Hellotime or Holdtime from hello messages. The Hellotime is used to determine the frequency of hello message generation when this router becomes the active or standby router. The Holdtime is the interval between the receipt of a Hello message and the presumption that the sending router has failed.

If the value of this object is "TRUE", the value of cHsrpGrpConfiguredHelloTime and cHsrpGrpConfiguredHoldTime are used. If the value of this object is "FALSE", the Hellotime and Holdtime values are learned.