Cisco PIX Firewall and VPN Configuration Guide, Version 6.2 - Firewall Configuration Forms [Cisco PIX Firewall Software]

Table Of Contents

Firewall Configuration Forms

PIX Firewall Network Interface Information

Routing Information

Network Address Translation

Static Address Translation

Inbound Access Control

Outbound Access Control

Authentication and Authorization

Firewall Configuration Forms

Installing PIX Firewall requires a thorough knowledge of your company's network topology and security policy. To get the PIX Firewall running immediately, fill in the information in Table A-1 to Table A-4, and proceed to Chapter 2, "Establishing Connectivity." To configure the PIX Firewall for specific types of network traffic, fill in the information in Table A-5 through Table A-8, and follow the instructions in Chapter 3, "Controlling Network Access and Use."

Information may not appear in the same order in the forms as it does in a configuration listing. The Cisco PIX Firewall Command Reference provides the complete syntax for all PIX Firewall commands.

This appendix includes the following sections:

•PIX Firewall Network Interface Information

•Routing Information

•Network Address Translation

•Static Address Translation

•Inbound Access Control

•Outbound Access Control

•Authentication and Authorization

For specific information about your network environment, contact your network administrator.

PIX Firewall Network Interface Information

Each PIX Firewall has two or more physical network interfaces. Configure each interface with an IP address, network speed, maximum transmission unit (MTU) size, and so on. Refer to the interface command page within the Cisco PIX Firewall Command Reference for complete information on the interface command. Table A-1 provides a form for entering PIX Firewall network interface information.

Table A-1 PIX Firewall Network Interface Information

Interface Name

Interface Type

Hardware ID

Interface

IP Address

Interface Speed

MTU Size

Interface Security Level

Outside

0

Inside

100

Routing Information

Table A-2 provides a form for entering route information. Refer to the Cisco PIX Firewall Command Reference for complete information on the route command and the rip command. The router IP addresses should not be the same as the PIX Firewall interface IP address, or the same as any global address specified in Table A-3.

Table A-2 Routing Information

Interface Name

Destination Network IP Address

Network Mask

Gateway (Router) IP Address

(RIP) Enable

Passive Listening for Routing Information? (Yes, No)

(RIP)

Broadcast This Interface as a Default Route? (Yes, No)

Network Address Translation

Table A-3 provides a form for gathering the global address pool information. Table A-4 links internal network addresses with the global pool information. The information in Tables A-3 and A-4 work together to set up NAT and PAT on the PIX Firewall. Refer to the Cisco PIX Firewall Command Reference for complete information on the global and nat commands.

Table A-3 Outside (Global) Network Address or Address Range

Outside or Perimeter Interface Name

NAT ID Number from Table A-3

Beginning of IP Address Range

End of IP Address Range (Optional)¹

Comments

¹Do not enter an ending IP address for PAT assignments. PAT uses only a single IP address.

Table A-4 maps internal (inside) or perimeter network addresses with global network addresses on other interfaces in the PIX Firewall.

Table A-4 Inside (Local) or Perimeter Network Address Translation

Inside or Perimeter Name from Table A-1

NAT ID Number

(1 to 65,000)

Network Address Mapped to the NAT ID

Network Mask for This Address

Comments

Static Address Translation

We recommend completing the information in Tables A-1 to A-4 and completing the instructions provided in Chapter 2, "Establishing Connectivity" before attempting advanced configuration. After completing and testing your basic configuration, complete the information in Table A-5, which defines advanced configuration settings for static address mapping. Then refer to Chapter 3, "Controlling Network Access and Use," for instructions about how to use this information. Refer to the Cisco PIX Firewall Command Reference for complete information on the static command.

Note Static addresses should not be members of the global address pool specified in Table A-3. If the internal host requires Internet access, the static address should be a NIC-registered address.

Table A-5 Static Address Mapping

Interface on Which the

Host Resides

Interface Name Where the Global Address Resides

Host IP Address

Static IP Address

Comments

Inbound Access Control

Before attempting advanced configuration, we recommend completing the information on Tables A-1 to A-4 and completing the instructions provided in Chapter 2, "Establishing Connectivity." After completing and testing your basic configuration, complete the information in Table A-6, which defines advanced configuration settings for inbound access control. Then refer to Chapter 3, "Controlling Network Access and Use," for instructions about how to use this information. Refer to the Cisco PIX Firewall Command Reference for complete information on the access-list and access-group commands.

To control access by IP address, configure an access-list command statement. To control access by user, set up authentication, as shown in Table A-8. A global or static address should exist for an internal host or network before you can set up a access-list command statement. See Tables A-3 and A-5 to configure a global or static entry for an internal host.

Table A-6 Inbound Access Control

Access List Identifier

Permit or Deny

Network Protocol: UDP, TCP, ICMP, or Number

Source Address:
External Host or Network IP Address(es) and Network Mask

Destination Address:
Static IP Address and Network Mask from Table A-5¹

Destination Ports ²

Interface To
Bind List

¹Use the keyword "any" to specify all global IP addresses.

²To specify a single port or a range of ports, you can use operands: greater than, less than, equal, not equal, and range.

The following is a list of literal port names that you can use when configuring an access-list command statement: DNS, ESP, FTP, H323, HTTP, IDENT, NNTP, NTP, POP2, POP3, PPTP, RPC, SMTP, SNMP, SNMPTRAP, SQLNET, TCP, Telnet, TFTP, and UDP. You can also specify these ports by number. Port numbers are defined in RFC 1700.

You should have two access-list command statement definitions to permit access to the following ports:

•DNS, Discard, Echo, Ident, NTP, RPC, SUNRPC, and Talk each require one definition for TCP and one for UDP.

•PPTP requires one definition for port 1723 on TCP and another for port 0 and GRE.

•TACACS+ requires one definition for port 65 on TCP and another for port 49 on UDP.

Outbound Access Control

Before performing advanced configuration, we recommend completing the information on Tables A-1 to A-4 and completing the instructions provided in Chapter 2, "Establishing Connectivity." After completing and testing your basic configuration, complete the information in Table A-6, which defines advanced configuration settings for inbound access control. Then refer to Chapter 3, "Controlling Network Access and Use," for instructions about how to use this information. Refer to the Cisco PIX Firewall Command Reference for complete information on the access-list and access-group commands. To configure access control by IP address, complete the form provided in Table A-7. To control access by user, set up authentication, as defined in Table A-8.

Table A-7 Outbound Access Control

Access List Identifier

Permit or Deny

Network Protocol: UDP, TCP, or Number

Source Address:
External Host or Network IP Address(es) and Network Mask

Destination Address or Network IP and Network Mask from Table A-5¹

Destination Ports (Services) ²

Interface To
Bind Access List To

¹Use the keyword "any" to specify all global IP addresses.

²To specify a single port or a range of ports, you can use operands: greater than, less than, equal, not equal, and range.

You can also specify a port with the source address, but this is seldom used.

Precede host addresses with the host parameter.

Use the interface name with the access-group command.

Refer to Appendix D, "TCP/IP Reference Information," for a list of protocol values. In addition, you can specify protocols by number.

Authentication and Authorization

Before performing the advanced configuration defined in Table A-8, we recommend completing the information on Tables A-1 to A-4 and completing the instructions provided in Chapter 2, "Establishing Connectivity." After completing and testing your basic configuration, complete the information in Table A-6, which defines advanced configuration settings for inbound access control. Then refer to Chapter 3, "Controlling Network Access and Use," for instructions about how to use this information. Refer to the Cisco PIX Firewall Command Reference for complete information on the aaa command.

Table A-8 defines the information needed applications that provide user authentication and authorization for network connections. Authentication servers include TACACS+ and RADIUS.

Note If your configuration requires a host on an outside (lower security level) interface to initiate connections with a host on a local (higher security level) interface, create static and access-list command statements for that connection as defined in Tables A-5 and A-6.

Prior to defining authentication and authorization requirements, identify the authentication server you are using, along with the IP address of the server, and the server encryption key on the PIX Firewall. Enter the information in the following form:

Authentication server (TACACS+ or RADIUS):_________________________

IP address: _________________________ Encryption key:_________________________

If you have additional authentication servers, list them separately.

Table A-8 Authentication and Authorization

Select Authentication or Authorization

Interface Name On Which to Authenticate or Authorize Connections

Protocol That Will Be Used to Provide Authentication: ANY, FTP, HTTP, TELNET

Authentication Server Type: TACACS+
or RADIUS

Local Host or Network IP Address¹ and Network Mask

Foreign Host or Network IP Address² and Network Mask

¹For a local interface, this is the internal host or network address from which connections originate. For an outside interface, this is the internal host or network address to which connections are sought.

²For a local interface, this is the internal host or network address to which connections are sought. For an outside interface, this is the external host or network address from which connections originate.