This section will help to guide the less-experienced user through the process of filling out the Network Information Sheet (Appendix C). Once filled out, that sheet will be referenced in many of the subsequent tasks to complete a procedure. In addition, the Network Information Sheet should be a handy reference document when troubleshooting problems with your network or firewall.
In block 1, enter the External IP Address for your firewall. This is the address that was provided to you by your ISP, or if you were given an IP address range, the address in that range that you want the firewall to have. Note that this address may not end in a 0 or 255. If you receive your network settings via DHCP (that is, your IP address is not static, but rather changes from time to time), enter 1.1.1.2. If you are a home user, subscribing to Internet services from an ISP, they must either provide you with this address, or inform you that you will be obtaining an address via DHCP.
In block 2, enter a secondary IP address for the external interface if you require one. If you are a home user, subscribing to an ISP for basic Internet services, you likely will not have a secondary IP address. Business customers who lease a range of addresses may wish to assign a second IP address to the external interface. One example where having a secondary IP address assigned to the external interface would be to make more than one www server on the private network available to the public.
In block 3, enter your broadcast address. If you receive your IP configuration from a DHCP server, enter a '+' here. If you are a home user who has subscribed to Internet services, your ISP must give you this number, or inform you that you will be getting your network settings via DHCP. If you need to figure this number out, you will need the IP address, the subnet mask, and a subnet calculator. See the Resources section for links to subnet calculators.
In block 4, enter your subnet mask. Typically, this number is either 255.255.255.0, or 255.255.0.0. There are cases, however where these numbers may not work. If you are leasing an IP address range with fewer than 254 addresses, your ISP may have subnetted the address range. A subnet calculator will help in figuring this number out, if you do not have it. You ISP should be able to give you the subnet mask, however. If you receive your network settings via DHCP, enter a 255.255.255.252
In block 5, enter your starting and ending IP addresses in your range. This is only for those who have leased a range of IP addresses. Most home users subscribing to Internet services will not need to enter anything here. Your ISP should be able to provide you with these addresses.
In block 6, enter the external gateway. This is the router where packets go after they leave the firewall destined for the Internet. This may also be called a "gateway", or "default gateway". Your ISP should give you this number when your service is established. If you get your IP configuration from a DHCP server, enter 1.1.1.1 here.
In block 7, enter your external network address. If you receive your network settings from a DHCP server, you can leave this block empty. If you use a static IP address, and do not know your network address, you can use a subnet calculator to figure it out, if you have your IP address and subnet mask. A simple way to figure it out is to replace all 255s in your subnet mask with the corresponding numbers from your IP address. What's left over should be your network address. Example 1: IP=111.222.333.444, SNM=255.255.255.0. The network address would be 111.222.333.0. Example 2: IP=111.222.333.444, SNM=255.255.255.127. The network address would be 111.222.333.127
In block 8, enter the external mask number. If you receive your network settings from a DHCP server, enter a 30. This is a number between 1 and 32 that represents your subnet mask. Some subnet calculators will give this number. Here are some of the more common numbers: Example 1: SNM=255.0.0.0. The mask number is 8. Example 2: SNM=255.255.0.0. The mask number is 16. Example 3: SNM=255.255.255.0. The mask number is 24. Example 4: SNM=255.255.255.127. The mask number is 25.
In block 9, enter the IP address of the internal interface on your firewall. For most situations, you can stick with the default 192.168.1.254. If you need to select a different IP address, remember that it cannot end in 0 or 255. Remaining procedures in this document assume an internal IP address of 192.168.1.254.
In block 10, enter your internal broadcast address. If you are using the default, this will be 192.168.1.255. You can also just enter a '+' sign, thus allowing Dachstein to figure out the details.
In block 11, enter your internal subnet mask. If you are sticking with the default, this will be 255.255.255.0.
In block 12, enter your internal address range. If you are sticking with the default settings, this will be Start: 192.168.1.1 and End: 192.168.1.254.
In block 13, enter your internal gateway. This applies only to those who are installing the firewall into a wide-area network with more than one IP network being routed through the firewall. This internal gateway is typically a router. I have also seen it referred to as a foreign router. Few home users will need to enter anything here.
In block 14, enter your internal network address. See step 7 for more information on network addresses. If you are using the default settings, this will be 192.168.1.0.
In block 15, enter your internal mask number. If you are sticking with the default, this number will be 24.
In block 16, enter a hostname for your firewall. This can be any name used to identify this system as a device on the network, though something short is advisable. In some situations, you may be assigned a hostname by your ISP. If this is the case, enter that hostname. For example, one ISP uses hostnames in the following format: XNNNNNN-X, where X is a letter, and N is a digit.
In block 17, enter your primary DNS server address. If you receive your IP configuration from a DHCP server, enter 0.0.0.0 here. This should be provided by your ISP, or you should get this from a DHCP server (if you are connecting with DHCP).
In block 18, enter your secondary DNS server address if you have one. If you receive your IP configuration from a DHCP server, enter 0.0.0.0 here. This should be provided by your ISP, or you should get this from a DHCP server (if you are connecting with DHCP).
In block 19, enter your domain. This may come from your ISP if you subscribe to Internet services from a local ISP. If you are responsible for maintaining DNS information for your organization, this will be the domain you registered. Note that this does not include the hostname of your firewall or any servers.
Blocks 20 through 27 should have been filled out when configuring the NICs.