Switch Services
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5.4 Configuring Switch Redundancy
Configuration and network monitoring are two tasks a network administrator faces as a network grows in
terms of the number of managed nodes (switches, routers, wireless devices etc.). Such scalability
requirements lead network administrators to look for managing and monitoring each node from a single
centralized management entity. The RFS7000 not only provides a centralized management solution, it provides
centralized management from any single switch in the network without restricting or dedicating one switch as
a centralized management node. This eliminates dedicating a management entity to manage all redundancy
members and eliminates the possibility of a single point of failure.
A redundancy group (cluster) is a set of switches (nodes) uniquely identified by group/cluster ID. Within the
redundancy group, members discover and establish connections to other group members. The redundancy
group has full mesh connectivity using TCP as the transport layer connection.
Up to 12 switches can be configured as members of a redundancy group to significantly reduce the chance of
a disruption in service to WLANs and associated MUs in the event of failure of a switch or intermediate
network failure. All members can be configured using a common file (cluster-config) using DHCP options. This
functionality provides an alternative method for configuring members collectively from a centralized location,
instead of configuring specific redundancy parameters on individual switches.
Configure each switch in the cluster by logging in to one participating switch. The administrator does not need
to login to each redundancy group member, as one predicating switch can configure each member in real-time
without “pushing” configurations between switches. A new CLI context called "cluster-cli" is available to set
the configuration for all members of the cluster. All switch CLI commands are considered cluster configurable.
In the example below, there are four switches (WS1, WS2, WS3 and WS4) forming a redundancy group. Each
switch has established a TCP connection with the others in the group. There is an additional CLI context called
cluster-context. A user/administrator can get into this context by executing a "cluster-cli enable" under the CLI
interface (future releases will have this support in the Web UI and SNMP interfaces). When the user executes
this command on WS1, WS1 creates a virtual session with the other switches in the redundancy group (WS2,
WS3 and WS4). Once the virtual session is created, any command executed on WS1 is executed on the other
Precision Displays the precision (accuracy) of the switch’s time clock (in Hz).
The values that normally appear in this field range from -6 for
mains-frequency clocks to -20 for microsecond clocks found in
some workstations.
Reference time Displays the time stamp at which the local clock was last set or
corrected.
Clock Offset Displays the time differential between switch time and the NTP
resource.
Root delay The total round-trip delay in seconds. This variable can take on both
positive and negative values, depending on the relative time and
frequency offsets. The values that normally appear in this field
range from negative values of a few milliseconds to positive values
of several hundred milliseconds.
Root Dispersion Displays the nominal error relative to the primary time source in
seconds. The values that normally appear in this field range from 0
to several hundred milliseconds.
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