Cisco Catalyst 3750-X User Manual

44-6
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 44 Configuring HSRP
Configuring HSRP
HSRP Configuration Guidelines
• HSRPv2 and HSRPv1 are mutually exclusive. HSRPv2 is not interoperable with HSRPv1 on an
interface and the reverse.
• In the procedures, the specified interface must be one of these Layer 3 interfaces:
– Routed port: a physical port configured as a Layer 3 port by entering the no switchport
interface configuration command.
– SVI: a VLAN interface created by using the interface vlan vlan_id global configuration
command and by default a Layer 3 interface.
– Etherchannel port channel in Layer 3 mode: a port-channel logical interface created by using
the interface port-channel port-channel-number global configuration command and binding
the Ethernet interface into the channel group. For more information, see the “Configuring
Layer 3 EtherChannels” section on page 40-15.
• All Layer 3 interfaces must have IP addresses assigned to them. See the “Configuring Layer 3
Interfaces” section on page 13-37.
• The version of an HSRP group can be changed from HSRPv2 to HSRPv1 only if the group number
is less than 256.
• If you change the HSRP version on an interface, each HSRP group resets because it now has a new
virtual MAC address.
• Only on mixed stacks of Catalyst 3750-X or Catalyst 3750-E and 3750 switches:
– HSRP for IPv4 and HSRP for IPv6 are mutually exclusive. You cannot enable both at the same
time.
– HSRP groups can be configured up to 32 instances.
– Configure only one instance of a First Hop Redundancy Protocol (FHRP). The switches support
HSRPv1, HSRPv2, and HSRP for IPv6.
– When configuring group numbers for HSRPv2 and HSRP for IPv6, you must use group numbers
in ranges that are multiples of 256. Valid ranges are 0 to 255, 256 to 511, 512 to 767, 3840 to
4095, and so on.
Examples of valid and invalid group numbers:
If you configure groups with the numbers 2, 150, and 225, you cannot configure another group
w
ith the number 3850. It is not in the range of 0 to 255.
If you configure groups with the numbers 520, 600, and 700, you cannot configure another
g
roup with the number 900. It is not in the range of 512 to 767.
Enabling HSRP
The standby ip interface configuration command activates HSRP on the configured interface. If an IP
address is specified, that address is used as the designated address for the Hot Standby group. If no IP
address is specified, the address is learned through the standby function. You must configure at least one
Layer 3 port on the LAN with the designated address. Configuring an IP address always overrides
another designated address currently in use.
When the st
andby ip command is enabled on an interface and proxy ARP is enabled, if the interface’s
Hot Standby state is active, proxy ARP requests are answered using the Hot Standby group MAC
address. If the interface is in a different state, proxy ARP responses are suppressed.

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing