![background image](/i/zyxel/144895/zyxel-zywall-2-ee/h/zyxel-zywall-2-ee-174.png)
ZyWALL 2 Series User’s Guide
11-18
Firewall
Screens
11.8 Predefined Services
The
Available
Services
list box in the
Rule Config
(uration) screen (see
Figure 11-4
) displays all predefined
services that the ZyWALL already supports. Next to the name of the service, two fields appear in brackets.
The first field indicates the IP protocol type (TCP, UDP, or ICMP). The second field indicates the IP port
number that defines the service. (Note that there may be more than one IP protocol type. For example, look at
the default configuration labeled “(
DNS
)”.
(UDP/TCP:53)
means UDP port 53 and TCP port 53. Custom
services may also be configured using the
Custom Ports
function discussed previously.
Table 11-5 Predefined Services
SERVICE
DESCRIPTION
AIM/New-ICQ(TCP:5190)
AOL’s Internet Messenger service, used as a listening port by ICQ.
AUTH(TCP:113) Authentication protocol used by some servers.
BGP(TCP:179)
Border Gateway Protocol.
BOOTP_CLIENT(UDP:68)
DHCP Client.
BOOTP_SERVER(UDP:67)
DHCP Server.
CU-SEEME
(TCP/UDP:7648, 24032)
A popular videoconferencing solution from White Pines Software.
DNS(UDP/TCP:53)
Domain Name Server, a service that matches web names (e.g.
www.zyxel.com.tw
) to IP numbers.
FINGER(TCP:79)
Finger is a UNIX or Internet related command that can be used to find out
if a user is logged on.
FTP(TCP:20.21)
File Transfer Program, a program to enable fast transfer of files, including
large files that may not be possible by e-mail.
H.323(TCP:1720) NetMeeting
uses this protocol.
HTTP(TCP:80)
Hyper Text Transfer Protocol - a client/server protocol for the world wide
web.
HTTPS(TCP:443)
HTTPS is a secured http session often used in e-commerce.
ICQ(UDP:4000)
This is a popular Internet chat program.
IKE(UDP:500)
The Internet Key Exchange algorithm is used for key distribution and
management.
IPSEC_TUNNEL(AH:0)
The IPSEC AH (Authentication Header) tunneling protocol uses this
service.