Sygate Single NIC Gateway

Sygate Technologies produce an Internet Gateway product called Sygate that fits quite nicely with NTL's CM service in the instance where you do not want a dedicated PC Gateway or a Hardware Router. In-built with Sygate is the ability to implement an Internet Router/NAT service using software running on a Windows 95, 98 or NT 2000 PC containing a single Network Card. Sygate do this with the use of a 'virtual' NIC. The real NIC is set-up as your CM facing interface and obtains it's IP address via the normal Windows' DHCP mechanism. The 'virtual' NIC runs on an IP range that is completely different to the IP network allocated by NTL, thus enabling an additional network to run on the same 'network' as your PC -> CM connection. The local machines are set with the 'virtual' IP address of the Sygate server as the default gateway.

Obtaining and Installing Sygate

Syagte is a nice 5MB download from as sygate.exe, which, when run produces a folder within which is the Sygate Home Network program, which actually installs the Sygate server. The installation prompts for either a server or client installation, and server is required if you want this machine to provide Internet access. Once installed Sygate can be configured to provide single NIC capability, DHCP services for your LAN, connection filtering and an add-on firewall function.

Sygate Configuration

After installation and a reboot, Sygate requires licensing information to be entered prior to running. The license key for the 30-day trial version is H1001001 and no other info is required in order to run the trial.

The routing engine of Sygate runs as a background process, and in order to see whether your Internet link is up, or to configure you need to run the Sygate Manager. The default manager screen is shown below:

Sygate Manager

Configuration is performed from the options available from the Advanced button on the main manger screen. Note that the Firewall, Access Rules and Permissions do not require any configuration by default for simple Internet Sharing.

Sygate Manager Advanced Configuration
For Configuring the Network Operation of Sygate

For access to the Sygate Firewall add-on

Access Rules
For adding access rules for various applications

Activity Log
Er, the activity log!

Allow or disallow connection to specified hosts.

Configuring Sygate to provide gateway services to your LAN is simply a case of telling Sygate which interface you are going to use for your Internet Connection, and whether you want to use a single NIC connection. To enable this and then add the Internal IP address that you wish your gateway to be. Note that in the screen dump below , the IP address shown underneath the selected NIC would normally be the address as supplied by NTL's DHCP server. The address shown in the example is one obtained by the Sygate PC NIC from our internal DHCP server, rather than NTL's. Operation, however, is identical.

When Single NIC is enabled, Sygate automatically sets the Gateway IP to, and this should be the address set as the client's default gateway.

Sygate Network Configuration

As can be seen from above the configuration of Sygate is quite straightforward with the options quite clearly labled. For instance, if you want to run a DHCP server internally, enable it here. Sygate will automatically assign a range of IP addresses but you can define your own from the options available from the Advanced button. Note that your DHCP range should be from the same IP subnet as your Sygate server is configured to be on, i.e., if Sygate Gateway IP is, then your DHCP range will need to withing the address range for that address, or from to if using the whole range.

Client Configuration

With DHCP enabled on Sygate, your client PCs need to be set to get their address automatically. If DNS is disabled within the TCP settings of the client, then the client should also discover it's DNS server as well as it's default gateway. Applications on the client PC need to be setup as tho' they have a direct connection to the Internet - remember that Sygate only provides NAT facilities, it does not provide proxy services, tho' some applications may need Access Rules defined in order for them to function correctly.

If no DHCP service is configured in Sygate, then client PCs require their TCP/IP settings to be set manually using a unique address from your network. The Gateway and DNS servers should be set to the Gateway address as defined in Sygate, e.g., if using the default address allocated by Sygate. Again, client applications will need to be set as tho' they are connected direct to the Internet.

There is the facility with Sygate to create Client Configuration disks, but in reality, all this does is set the IP address of the client and it is not really needed.


Sygate is an excellent way to share an Internet Connection without needing to buy additional hardware. The machine used for this trial was a Compaq Deskpro P133 with 16MB of RAM, with a single 3COM NIC and performance was suprisingly good. Note, however, Sygate is not free. It's smallest license costs $40, but this only supports three client PCs. More clients mean more cost, with there being a point at the 10 user level where a hardware router such as a Linksys is better VFM. Sygate also does not offer any firewalling capabilities beyond NAT, tho' there is a free Firewall add-on available.

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