About The Primary Lan And The Root Access Point - Intermec MobileLAN access WA2XG System Manual

About the Primary LAN and the Root Access Point

MobileLAN access WA2XG System Manual
The primary LAN (also called the root IP subnet) contains the root access
point, which initiates the spanning tree. When choosing the primary LAN,
ideally you should choose the IP subnet that contains gateways or servers
for the wireless end devices. However, these gateways and servers may also
be on another subnet.
The root access point coordinates the network and distributes common
system parameters to other access points and end devices. Consider these
selection criteria when choosing which access point to be the root:
• The root must be installed on the primary LAN.
• The root should be an access point that does not handle a large volume
of wireless traffic.
• The root should have the latest software release available because the
root distributes parameters to the child access points. In a mixed
network of WA2Xs and 210Xs, choose a WA21 or WA22 as the root.
• If your mixed network contains MobileLAN access products and 6710s,
configure a MobileLAN access product as the root.
The root is elected from a group of access points that are designated as root
candidates: access points that are powered on, active, and do not have a
root priority of 0. The access point with the highest root priority is the
root.
The election process also occurs in the event of a root access point failure.
Besides the root, you should have two or three access points with a non-
zero root priority. (Use the selection criteria listed earlier in this section to
determine which access points should be root candidates.) If two access
points have the same root priority, the access point with the highest
Ethernet address becomes the root. You should configure your network
with overlapping coverage so that the network can automatically recover
from any single point of failure.
After the root access point is elected, it transmits hello messages on all
enabled ports. The spanning tree forms as other access points receive hello
messages and attach to the network on the optimal path to the root. A
non-root access point also transmits hello messages after it is attached to
the network. Each hello message contains the LAN ID of the access point
that originated the message. IAPP does not allow wireless links to exist
between access points that do not have matching LAN IDs.
To configure a root access point
1 Using the selection criteria listed earlier in this section, determine which
access point to configure as the root.
2 On that access point, from the Navigation Menu click Spanning Tree
Settings. The Spanning Tree Settings screen appears.
Chapter 5 — Configuring the Spanning Tree
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