Cisco Nexus 3548 User Manual

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Cisco Nexus 3548 Switch NX-OS Unicast Routing Command Reference
OL-27852-01
Chapter Unicast Routing Commands
preempt (HSRP)
preempt (HSRP)
To configure a preemption delay, use the preempt command. To disable this feature, use the no form of
this command.
preempt [delay {minimum min-delay | reload rel-delay | sync sync-delay}]
no preempt [delay {minimum min-delay | reload rel-delay | sync sync-delay}]
Syntax Description
Command Default The default delay time for all options is 0 seconds.
Command Modes Interface configuration or HSRP template mode
Command History
Usage Guidelines Specifying a minimum delay allows routing tables to be updated before a router becomes active. When
a router first comes up, it does not have a complete routing table. A high-priority router will only delay
preemption if it first receives a hello packet from a low-priority active router. If the high-priority router
does not receive a hello packet from the low-priority active router when it is starting up, it assumes there
is no active router for the group and becomes active as soon as possible.
This command requires the LAN Base Services license.
Examples This example shows how to configure a delay when a router becomes active when its priority is 110:
switch# configure terminal
switch(config)# interface ethernet 0/1
switch(config-if)# no switchport
switch(config-if)# ip address 10.0.0.1 255.255.255.0
switch(config-if)# hsrp 4
switch(config-if-hsrp)# priority 110
switch(config-if-hsrp)# preempt
switch(config-if-hsrp)# authentication text sanjose
delay minimum
min-delay
(Optional) Specifies the minimum number of seconds that preemption is
delayed to allow routing tables to be updated before a router becomes
active. The default value is 0.
reload rel-delay (Optional) Specifies the time delay after the router has reloaded. This period
applies only to the first interface-up event after the router has reloaded. The
default value is 0.
sync sync-delay (Optional) Specifies the maximum number of seconds to allow IP
redundancy clients to prevent preemption. When this period expires,
preemption occurs regardless of the state of the IP redundancy clients. The
default value is 0.
Release Modification
5.0(3)A1(1) This command was introduced.

Cisco Nexus 3548 Specifications

General

Rack Units	1RU
Product Type	Switch
Form Factor	Rack-mountable
Jumbo Frame Support	9216 bytes
Input Voltage	100-240 VAC
Product Series	Nexus 3000
Model	Nexus 3548
Operating System	Cisco NX-OS
Ports	48 x 10GE SFP+
Latency	190 ns
Airflow	Front-to-back

Summary

New and Changed Information

Preface

Describes audience, organization, and conventions of the document.

Document Conventions

Explains conventions used in command descriptions and screen examples.

Related Documentation

Lists other Cisco documentation for related products.

Unicast Routing Commands

additional-paths receive

Enables BGP additional paths for a prefix to be received from a capable peer.

address-family (BGP neighbor)

Enters neighbor address family mode for configuring BGP routing protocols.

area authentication (OSPF)

Enables authentication for an Open Shortest Path First (OSPF) area.

aggregate-address (BGP)

Creates a summary address in a Border Gateway Protocol (BGP) routing table.

authentication (HSRP)

Configures authentication for the Hot Standby Router Protocol (HSRP).

distance (EIGRP)

Sets administrative distances for EIGRP internal and external routes.

redistribute (BGP)

Injects routes from one routing domain into the Border Gateway Protocol (BGP).

router bgp

Assigns an autonomous system (AS) number and enters BGP configuration mode.

neighbor

Configures a Border Gateway Protocol (BGP) neighbor and enters configuration mode.

Unicast Routing Show Commands

show bgp

Displays Border Gateway Protocol (BGP) routes.

show ip eigrp neighbors

Displays information about neighbors discovered by EIGRP.

show ip ospf neighbors

Displays Open Shortest Path First (OSPF)-neighbor information on a per-interface basis.

show ip route

Displays routes from the unicast Routing Information Base (RIB).

show running-config

Displays the running configuration.

show vrrp

Shows information about the Virtual Router Redundancy Protocol (VRRP).