Secure Computing sidewinder, Startup Manual

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Chapter 2: Planning Considerations
Preparing your Quick Start Wizard responses
10
What is your appliance’s fully qualified hostname?
Sidewinder appliance hostname: _________________________________
Enter the hostname by which the appliance will be known on the external burb
(Internet). Determine a naming scheme for your appliances or select a name
that fits with your existing scheme. For example, if you have more than one
appliance, your naming scheme could be
sidewinder_a.example.com ,
sidewinder_b.example.com , and so on.
What are the IP addresses and netmasks of your external and
internal interfaces?
External IP address/netmask or DHCP: ____________________________
Internal IP address/netmask: ____________________________________
Each network interface on an appliance must be given an IP address in a
network, or subnet, different from the other network interfaces. IP addresses
are added to the appliance’s routing table. An appliance uses its routing table
to select a network interface for each packet according to the destination IP
address, so the route to this address must map to only one network interface.
Each network interface corresponds to one burb. Burb is a term that refers to
an interface and all the systems it connects. From a security perspective, a
burb and the network it is attached to are a single entity covered by the same
security policy. The initial appliance configuration has two burbs: an
internal
burb and an external burb. You may assign additional burbs as needed, such
as a DMZ burb and virtual burb, once your appliance is fully operational.
Your
external interface
(external burb) is the network interface that handles
your external network. This is often, but not always, your network’s connection
to the Internet and the outside world. The external, or Internet, burb has unique
properties that are important when managing mail, DNS, and routing and is
usually your traffic’s most common termination point. Your security policy will
generally have strong restrictions controlling how traffic arriving on this network
interface is allowed to pass into your internal network. You may obtain an
address for this interface by one of two ways:
•
Automatically assign an external address using a Dynamic Host
Configuration Protocol (DHCP) server.
Note: If you select DHCP, your Admin Console must be in the internal burb.
•
Manually assign an IP address. (The netmask is automatically entered
once you type in an IP address. If the supplied netmask is incorrect, change
it before continuing.)
Your
internal interface
(internal burb) is the NIC that handles your internal
network. Users on the internal network are generally trusted, so your security
policy will allow more traffic out through an appliance than is allowed in.