The WAP571/E device supports the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP). ISATAP enables the WAP device to transmit IPv6 packets encapsulated within IPv4 packets over the LAN. The protocol enables the WAP device to communicate with remote IPv6-capable hosts even when the LAN that connects them does not support IPv6.
The WAP device acts as an ISATAP client. An ISATAP enabled host or router must reside on the LAN. The IP address or hostname of the router is configured on the WAP device (by default, it is isatap). If configured as a hostname, the WAP device communicates with a DNS server to resolve the name into one or more ISATAP router addresses. The WAP device then sends solicit messages to the router(s). When an ISATAP-enabled router replies with an advertisement message, the WAP device and router establish the tunnel. The tunnel interface is assigned a link-local and a global IPv6 address, which serve as virtual IPv6 interfaces on the IPv4 network.
When IPv6 hosts initiate communication with the WAP device connected via the ISATAP router, the IPv6 packets are encapsulated into IPv4 packets by the ISATAP router.
Configuring an IPv6 Tunnel Using ISATAP
To configure an IPv6 tunnel using ISATAP:
1. Select LAN > IPv6 Tunnel in the navigation area.
2. Configure the following parameters:
• ISATAP Status—Enables or disables the administrative mode of ISATAP on the WAP device.
• ISATAP Capable Host—The IP address or DNS name of the ISATAP router. The default value is isatap.
• ISATAP Query Interval—Specifies how often the AP should send queries to the DNS server to attempt to resolve the ISATAP host name into an IP address. The WAP sends DNS queries only when the IP address of an ISATAP router is unknown. The valid range is 120 to 3600 seconds. The default value is 120 seconds.
• ISATAP Solicitation Interval—Specifies how often the WAP should send router solicitation messages to the ISATAP router it learns about through the DNS query messages. The WAP sends router solicitation messages only when there is no active ISATAP router. The valid range is 120 to 3600 seconds. The default value is 120 seconds.
3. Click Save. The settings are saved to the Startup Configuration.
When the tunnel is established, the ISATAP IPv6 Link Local Address and ISATAP IPv6 Global Address show on the page. These are the virtual IPv6 interface addresses to the IPv4 network.