PIX Firewall permits the following TCP literal names: bgp, chargen, cmd, daytime, discard, domain, echo, exec, finger, ftp, ftp-data, gopher, h323, hostname, http, ident, irc, klogin, kshell, lpd, nntp, pop2, pop3, pptp, rpc, smtp, sqlnet, sunrpc, tacacs, talk, telnet, time, uucp, whois, and www. | APPENDIX D TCP IP Reference Information This appendix includes the following sections IP Addresses Ports Protocols and Applications Using Subnet Masks IP Addresses IP address classes are defined as follows - Class A If the first octet is between 1 and 127 inclusive the address is a Class A address. In a Class A address the first octet is the one-byte net address and the last three octets are the host address. The network mask for Class A addresses is . - Class B If the first octet is between 128 and 191 inclusive the address is a Class B address. In a Class B address the first two octets are the net address and the last two octets are the host address. The network mask for Class B addresses is . - Class C If the first octet is 192 or higher the address is a Class C address. In a Class C address the first three octets are the net address and the last octet is the host address. The network mask for Class C addresses is . - Class D These addresses are used for multicast transmissions and within the range from to . Some of these addresses are assigned to multicasts used by specific TCP IP protocols. Other Class D addresses are assigned to applications such as streaming video that send data to many recipients simultaneously. For information about enabling the PIX Firewall to transmit multicast traffic refer to Enabling Stub Multicast Routing in Chapter 2 Establishing Connectivity. We recommend that you use RFC 1918 IP addresses for inside and perimeter addresses. These addresses follow - Class A to - Class B to - Class C to - Class D to Cisco PIX Firewall and VPN Configuration Guide I 78-13943-01 D-1 Appendix D TCP IP Reference Information Ports PIX Firewall requires that IP addresses in the ip address static global failover and virtual commands be unique. These IP addresses cannot be the same as your router IP
