User Manual

M4300 Intelligent Edge Series Fully Managed Stackable Switches
Manage Stacking User Manual167
For NSF to be effective, adjacent networking devices must not reroute traffic around the
restarting device. The switch uses three techniques to prevent traffic from being rerouted:
• A protocol can distribute a part of its control plane to stack units so that the protocol can
give the appearance that it is still functional during the restart. Spanning tree and port
channels use this technique.
• A protocol can enlist the cooperation of its neighbors through a technique known as
graceful restart. OSPF uses graceful restart if it is enabled.
• A protocol can restart after the failover if neighbors react slowly enough that they cannot
normally detect the outage.
The IP multicast routing protocols are a good example of this
behavior.
To take full advantage of nonstop forwarding, Layer 2 connections to neighbors must be
through port channels that span two or more stack units, and Layer 3 routes must be ECMP
routes with next hops through physical ports on two or more units.
The hardware can quickly
move traffic flows from port channel members or ECMP paths on a failed unit to a surviving
unit.
Configure a Stack
You can move the primary management unit functionality from one unit to another. Upon
execution, the entire stack (including all interfaces in the stack) is unconfigured and
reconfigured with the configuration on the new primary management unit. After the reload is
complete, all stack management capability must be performed on the new primary
management unit. To preserve the current configuration across a stack move, save the
current configuration to the NVRAM before performing the stack move. A stack move causes
all routes and Layer 2 addresses to be lost. The administrator is prompted to confirm the
management move.
Select a New Stack Master
To select a new stack master:
1. Launch a web browser
.
2. In the address field of your web browser
, enter the IP address of the switch.
The login window opens.
3. Enter admin as the user name, enter your local device password,
and click the Login
button.
The first time that you log in, no password is required. However, you then must specify a
local device password to use each subsequent time that you log in.
The System Information page displays.
4. Select System > Stacking > Basic > Stack Configuration.