Extreme Networks Altitude 4700 Series, Руководство по продукции

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Configuring Mesh Networking
Altitude 4700 Series Access Point Product Reference Guide
580
Defining the Mesh Topology
When a user wants to control how the spanning tree determines client bridge connections, they need to
control the mesh configuration. The user must be able to define one node as the root. Assigning a base
bridge the lowest bridge priority defines it as the root.
NOTE
Extreme Networks recommends using the Mesh STP Configuration screen to define a base bridge as a
root. Only advanced users should use the Advanced Client Bridge Settings screen’s Preferred List to define the
mesh topology, as omitting a bridge from the preferred list could break connections within the mesh network.
The Access Point can manipulate the path cost assigned to a bridge connection based on that
connection’s RSSI. This results in the spanning tree selecting the optimal path for forwarding data when
redundant paths exist. However, this can be overridden using the preferred list. When using the
preferred list, the user enters a priority for each bridge, resulting in the selection of the forwarding link.
Limit the wireless client’s connections to reduce the number of hops required to get to the wired
network. Use each radio’s
preferred base bridge list to define which Access Points the client bridge
connects to. For more information, see “Configuring Mesh Networking Support” on page 581 .
Mesh Networking and the Access Point’s Two Subnets
The Access Point now has a second subnet on the LAN side of the system. This means wireless clients
communicating through the same radio can reside on different subnets. The addition of this feature
adds another layer of complexity to the Access Point’s mesh networking functionality.
With a second LAN introduced, the LAN’s Ethernet port (and any of the 16 WLANs) could be assigned
to one of two different subnets. From a layer 2 perspective, the system has two different bridge
functionalities, each with its own STP. The WLAN assignment controls the subnet (LAN1 or 2) upon
which a given connection resides. If WLAN2 is assigned to LAN1, and WLAN2 is used to establish a
client bridge connection, then the mesh network connection resides on LAN1.
Therefore, (depending upon the WLAN-to-LAN mapping), the Access Point could have multiple mesh
connections on either LAN1 or LAN2.
Normal Operation
Once the mesh network is defined, all normal Access Point operations are still allowed. MUs are still
allowed to associate with the Access Point as usual. The user can create WLANs, security polices and
VLANs as with any other Access Point. DHCP services function normally and all layer 3
communications are allowed.
WNMP is used to send information about each mesh network so information can be displayed to the
user from any Access Point on the system. WNMP messages are AP-AP info messages used to send
system status.