Cisco Catalyst 3750-E User Manual

6-5
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 6 Clustering Switches
Planning a Switch Cluster
• SNMP Community Strings, page 6-14
• Switch Clusters and Switch Stacks, page 6-14
• TACACS+ and RADIUS, page 6-16
• LRE Profiles, page 6-16
See the release notes for the list of Catalyst switches eligible for switch clustering, including which ones
ca
n be cluster command switches and which ones can only be cluster member switches, and for the
required software versions and browser and Java plug-in configurations.
Automatic Discovery of Cluster Candidates and Members
The cluster command switch uses Cisco Discovery Protocol (CDP) to discover cluster member switches,
candidate switches, neighboring switch clusters, and edge devices across multiple VLANs and in star or
cascaded topologies.
Note Do not disable CDP on the cluster command switch, on cluster members, or on any cluster-capable
switches that you might want a cluster command switch to discover. For more information about CDP,
see Chapter 27, “Configuring CDP.”
Following these connectivity guidelines ensures automatic discovery of the switch cluster, cluster
ca
ndidates, connected switch clusters, and neighboring edge devices:
• Discovery Through CDP Hops, page 6-5
• Discovery Through Non-CDP-Capable and Noncluster-Capable Devices, page 6-6
• Discovery Through Different VLANs, page 6-7
• Discovery Through Different Management VLANs, page 6-7
• Discovery Through Routed Ports, page 6-8
• Discovery of Newly Installed Switches, page 6-9
Discovery Through CDP Hops
By using CDP, a cluster command switch can discover switches up to seven CDP hops away (the default
is three hops) from the edge of the cluster. The edge of the cluster is where the last cluster member
swi
tches are connected to the cluster and to candidate switches. For example, cluster member switches 9
an
d 10 in Figure 6-1 are at the edge of the cluster.
In Fi
gure 6-1, the cluster command switch has ports assigned to VLANs 16 and 62. The CDP hop count
is three. The cluster command switch discovers switches 11, 12, 13, and 14 because they are within three
hop
s from the edge of the cluster. It does not discover switch 15 because it is four hops from the edge of
the cluster.

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