Cisco WS-C3550-12G Software Configuration Manual page 117

Chapter 5 Clustering Switches
Discovery through CDP Hops
By using CDP, a 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 member switches are
connected to the cluster (for example, the command switch and member switches 8, 9, and 10 in
Figure 5-1
You can set the number of hops the command switch searches for candidate and member switches by
selecting Cluster > Hop Count. When new candidate switches are added to the network, the command
switch discovers them and adds them to the list of candidate switches.
Figure 5-1
VLANs 16 and 62. The CDP hop count is three. The command switch discovers switches 11, 12, 13, and
14 because they are within 3 hops from the edge of the cluster. It does not discover switch 15 because it
is 4 hops from the edge of the cluster.
Figure 5-1
Edge of
cluster
78-11194-03
are at the edge of the cluster).
shows a switch cluster with candidate switches. The command switch has ports assigned to
Discovery through CDP Hops
Catalyst 3550
command switch
Si
VLAN 16
Member
switch 8
Member
switch 9
Switch 11
candidate
switch
VLAN 62
Member
switch 10
Switch 12
Candidate
Switch 13
switches
Switch 14
Switch 15
Catalyst 3550 Multilayer Switch Software Configuration Guide
Planning a Switch Cluster
5-5