Cisco Catalyst 3750-E User Manual

42-3
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 42 Configuring HSRP
Understanding HSRP
Figure 42-1 Typical HSRP Configuration
HSRP Versions
Cisco IOS Release 12.2(46)SE and later support these Hot Standby Router Protocol (HSRP) versions:
• HSRPv1—Version 1 of the HSRP, the default version of HSRP. It has these features:
– The HSRP group number can be from 0 to 255.
– HSRPv1 uses the multicast address 224.0.0.2 to send hello packets, which can conflict with
Cisco Group Management Protocol (CGMP) leave processing. You cannot enable HSRPv1 and
CGMP at the same time; they are mutually exclusive.
• HSRPv2—Version 2 of the HSRP has these features:
– To match the HSRP group number to the VLAN ID of a subinterface, HSRPv2 can use a group
number from 0 to 4095 and a MAC address from 0000.0C9F.F000 to 0000.0C9F.FFFF.
– HSRPv2 uses the multicast address 224.0.0.102 to send hello packets. HSRPv2 and CGMP
leave processing are no longer mutually exclusive, and both can be enabled at the same time.
– HSRPv2 has a different packet format than HRSPv1.
A switch running HSRPv1 cannot identify the physical router that sent a hello packet because
t
he source MAC address of the router is the virtual MAC address.
Host B
172.20.130.5
172.20.128.32
Host A
172.20.128.55
172.20.128.1 172.20.128.3 172.20.128.2
Virtual
router
Active
router
Standby
router
Router A Router B
101361
Host C

Cisco Catalyst 3750-E Specifications

General

Series	Catalyst 3750-E
Switching Capacity	32 Gbps
Stacking Bandwidth	32 Gbps
StackWise Plus	Yes
Layer Support	Layer 3
MAC Address Table Size	12, 000 entries
RAM	256 MB
Flash Memory	64 MB
Memory	256 MB DRAM, 64 MB Flash
Operating Temperature	32 to 113°F (0 to 45°C)
Ports	48 10/100/1000 Ethernet ports
Form Factor	Rack-mountable
Jumbo Frame Support	Yes
Input Voltage	100 to 240 VAC
Storage Temperature	-25 to 70 °C
Relative Humidity	10 to 90% non-condensing