User's Guide

AirTight Management Console User Guide
50
A bridged network is used when the AP and the clients associating with the AP can be in the same
subnet.
Similarly, network Address Translation (NAT) must be used when you want to have the clients in a
separate subnet and the AP is in a separate subnet. With NAT, the clients can have a private IP address
pool and it is easier to add more clients to the network as they do not require a public IP address.
A wireless LAN, on which NAT is enabled, can be extended to the wired side using the second Ethernet
port present on the Access Point device. Create an isolated wired LAN with one or more wired devices
connected through layer-2 switches and connect the second Ethernet port of the Access Point to this
wired subnet. The wired LAN will be an extension of the wireless LAN of this SSID profile with NAT
enabled. All network settings like NAT and portal, configured on this SSID profile, are also applicable to
the wired devices.
Note: The second Ethernet port is available on some specific AirTight device models only.
When you are configuring NAT parameters, you must specify at least one DNS server. On successful
association, wireless clients will get the specified DNS servers. You can specify up to three such DNS
server IP addresses.
Generic Routing Encapsulation (GRE) is useful when you want to route network traffic from and to a
single end point and apply policies on this end point.
IMPORTANT: GRE works only when NAT is enabled.
To configure network address translation settings, do the following.
1.
Specify the VLAN ID for which the bridging or NAT settings would be applicable.
2.
Select the NAT check box if you want to enable NAT.
3.
Specify the following NAT related settings if you have enabled NAT.
Field
Description
NAT
Select this check box to enable NAT (network address translation).
Enable NAT if you want to enable wired extension.
Start IP
address
The starting IP address of the DHCP address pool in the selected
network ID.
End IP
address
The end IP address of the DHCP address pool in the selected
network ID.
Local IP
address
An IP address in selected network ID outside of the DHCP address
pool. This address is used as the gateway address for the guest
wireless network.
Subnet Mask
The net mask for the selected network ID.
Lease Time
The DHCP lease time in minutes. Minimum value is 30
minutes,maximum value is 1440 minutes.
DNS Servers
The DNS servers that the wireless clients can make DNS queries to.
You can specify upto 3 DNS servers.
Enable
Wired
Extension
Select this check box to extend this wireless LAN to the wired side
using the second Ethernet port present on AirTight device functioning
as an access point.
4.
Select GRE if you want to enable Generic Routing Encapsulation (GRE).
The following table describes the Generic Routing Encapsulation related fields
Field
Description
GRE
Select this check box to enable Generic Routing Encapsulation and to