How to Allow Secure Connections Through a Firewall

Sally works in an office that uses a firewall to protect the company’s network while connected to the Internet. George works from home and needs to transfer his files to Sally. In this tutorial, you’ll learn how, using Laplink Gold 11.0, George now securely connects to Sally’s computer without the network administrator compromising the security of the firewall by opening a port.

IMPORTANT NOTES:

• Note 1) Do not duplicate the settings on both host & guest. There can be only one unconfigured firewall or router, not one at both ends of the connection. If you have more than one firewall, you must configure the guest computer (George) with the steps described in Tech Doc #633 - Overview for Configuring a Firewall or Router to Allow Laplink Connections.
• Note 2) This may not circumvent firewall software.

At the office, Sally configures Laplink in three areas.

• She changes Laplink’s Security to allow George to connect to her computer using Laplink services (for example, file transfer and remote control).
• She creates an entry in Laplink’s Address Book that tells the Firewall service it’s okay to let George connect to her.
• She publishes an Internet address to the Internet Directory Locator so that she doesn’t need to worry about knowing the IP address of her computer when George needs to connect to her.

Some of the information she uses must match George’s computer, so she collaborates with him at some stages.

Here are the steps Sally follows to change Laplink’s Security:

1. From Laplink’s Options menu, click Security. Or click the Security icon on the Link bar.
   
2. On the General tab, click Log-in List Only (Protected System).
   
3. Click Log-in List, and then click Add.
4. Type a log-in name and a password.
5. Click any Laplink services that you want this user to use when connected to this computer.
6. Click Apply, and then OK until the Security dialog box closes.

Note: Alternatively, you can set Laplink’s Security to Anybody (Public System). If you do so, click Public Privileges and set the Laplink services that you want everyone to use.

Here are the steps Sally follows to change Laplink’s Address Book:

1. From Laplink’s Options menu, click Address Book. Or click the Address Book icon on the Link bar.
   
2. Click Add.
3. In the Description field, add information that meaningfully describes to you what this connection does.
4. In the Computer Name, add the Laplink computer name of the computer that is connecting to you from outside the firewall.
   Note: This is information that came from George. He found it by going to Laplink’s Options menu, and clicking Computer name. George used george@home.)
5. In the Connection field, click Firewall.
6. In the Security Information to send fields, type the login name and password that you need to connect to the other computer. (This information also came from George. He has changed his Laplink Log-in List to let Sally connect to him.)
7. Click OK and then Close.

Here are the steps Sally follows to publish her Internet Address to the Internet Directory Locator:

1. From Laplink’s Options menu, click Internet Directory Options.
2. In the Internet address field, type a name that uniquely describes this computer. This can be an email name or something else.
3. In Options, click both boxes.
4. Under Directory server, confirm that the Laplink directory server is selected.
5. Click Apply and then OK.
6. Watch for the icon to appear in the Laplink status tray. If necessary, go to Laplink’s Connect menu and click Publish My Internet Address.
   Note: Click Don’t show me this message again if you want Laplink to automatically publish your address.D
   

Sally’s computer at work is now configured for George to connect to her. She needs to remember to leave Laplink running, and make sure that her computer has access to the Internet.

At home, George configures Laplink in these two areas:

• He changes Laplink’s Security to match Sally’s 'firewall' Address Book entry.
• He creates an entry in Laplink’s Address Book that has Sally’s Internet Address and the log-in name and password she assigned for him.

Here are the steps George follows to change Laplink’s Security, matching his Log-in List to Sally’s Address Book:

1. From Laplink’s Options menu, click Security. Or click the padlock icon on the Link Bar.
2. On the General tab, click Log-in List Only (Protected System).
3. Click Log-in List, and then click Add.
4. Type the log-in name and password.
5. Note: This is the information he gave to Sally for her Address Book.
6. For Services, click Firewall. (This is what tells Sally’s computer it’s okay for George to connect.)
7. Click Apply, and then OK until the Security dialog closes.

Here are the steps George follows to create his Address Book entry:

1. From Laplink’s Options menu, click Address Book. Or click the Address Book icon on the Link bar.
   
2. Click Add.
3. In the Description field, add information that meaningfully describes to you what this connection does.
4. In the Computer Name, type the Laplink computer name of the computer that you are connecting to inside the firewall.
   Note: This is information that came from Sally. She found it by going to Laplink’s Options menu, and clicking Computer name. Sally used sally@work.
5. In the Connection field, click Internet.
6. For Services, click any Laplink service that you want to use. George is using File Transfer.
   Note: If you don’t have permission to use a service, you’ll see a message stating that Access is Denied.
7. In the Security Information to send fields, type the login name and password that you need to connect to the other computer. (This information came from Sally’s Log-in List.)
8. Click OK and then Close.

Here are the steps George follows to connect to Sally:

1. From Laplink's Connect Over menu in Laplink Gold 11.0 & 11.3, click Internet. For Laplink Gold 11.5, choose "Connect over ILS" from the Connect menu (above link bar).
2. Highlight the Address Book entry for the computer inside the firewall. (In George’s case, this is Sally’s Firewall @ work.)
3. Click OK.

   When the computers have connected, the file transfer (or other service) window appears on your screen. Here is what George saw.