•DHCP address serving can automatically serve the WAN IP address to a LAN computer.
When DHCP is used for addressing the designated passthrough PC, the acquired or configured WAN address is passed to DHCP, which will dynamically configure a
•If you want to manually assign the WAN address to a LAN PC, do not check the DHCP Enable checkbox.
•If you check the DHCP Enable checkbox, the screen expands.
The Host Hardware Address field displays. Here you enter the MAC address of the designated IP- Passthrough computer.
•If this MAC address is not all zeroes, then it will use DHCP to set the LAN host's address to the (config- ured or acquired) WAN IP address.
The MAC address must be six
•If you leave the MAC address as zeros then the first DHCP client will be assigned the WAN address.
Once configured, the passthrough host's DHCP leases will be shortened to two minutes. This allows for timely updates of the host's IP address, which will be a private IP address before the WAN connection is established. After the WAN connection is established and has an address, the passthrough host can renew its DHCP address binding to acquire the WAN IP address.
Arestriction. Since both the Gateway and the passthrough host will use the same IP address, new ses- sions that conflict with existing sessions will be rejected by the Gateway. For example, suppose you are a teleworker using an IPSec tunnel from the Gateway and from the passthrough host. Both tunnels go to the same remote endpoint, such as the VPN access concentrator at your employer’s office. In this case, the first one to start the IPSec traffic will be allowed; the second one – since, from the WAN, it's indistinguish- able – will fail.
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