ZyWALL USG 50-H User’s Guide
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Services
30.1 Overview
Use service objects to define TCP applications, UDP applications, and ICMP messages. You
can also create service groups to refer to multiple service objects in other features.
30.1.1 What You Can Do in the Service Screens
• Use the
Service
screens (
) to view and configure the ZyWALL’s
list of services and their definitions.
• Use the
Service Group
screens (
) to view and configure the
ZyWALL’s list of service groups.
30.1.2 What You Need to Know About Protocols
IP Protocols
IP protocols are based on the eight-bit protocol field in the IP header. This field represents the
next-level protocol that is sent in this packet. This section discusses three of the most common
IP protocols.
Computers use Transmission Control Protocol (TCP, IP protocol 6) and User Datagram
Protocol (UDP, IP protocol 17) to exchange data with each other. TCP guarantees reliable
delivery but is slower and more complex. Some uses are FTP, HTTP, SMTP, and TELNET.
UDP is simpler and faster but is less reliable. Some uses are DHCP, DNS, RIP, and SNMP.
TCP creates connections between computers to exchange data. Once the connection is
established, the computers exchange data. If data arrives out of sequence or is missing, TCP
puts it in sequence or waits for the data to be re-transmitted. Then, the connection is
terminated.
In contrast, computers use UDP to send short messages to each other. There is no guarantee
that the messages arrive in sequence or that the messages arrive at all.
Both TCP and UDP use ports to identify the source and destination. Each port is a 16-bit
number. Some port numbers have been standardized and are used by low-level system
processes; many others have no particular meaning.
Unlike TCP and UDP, Internet Control Message Protocol (ICMP, IP protocol 1) is mainly
used to send error messages or to investigate problems. For example, ICMP is used to send the
response if a computer cannot be reached. Another use is ping. ICMP does not guarantee
delivery, but networks often treat ICMP messages differently, sometimes looking at the
message itself to decide where to send it.
Содержание ZyWall USG 50-H Series
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Страница 10: ...Safety Warnings ZyWALL USG 50 H User s Guide 10...
Страница 28: ...Table of Contents ZyWALL USG 50 H User s Guide 28...
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Страница 34: ...Chapter 1 Introducing the ZyWALL ZyWALL USG 50 H User s Guide 34...
Страница 40: ...Chapter 2 Features and Applications ZyWALL USG 50 H User s Guide 40...
Страница 92: ...Chapter 5 Configuration Basics ZyWALL USG 50 H User s Guide 92...
Страница 130: ...Chapter 6 Tutorials ZyWALL USG 50 H User s Guide 130...
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Страница 156: ...Chapter 8 Interface ZyWALL USG 50 H User s Guide 156 Figure 128 Network Interface Ethernet Edit wan2...
Страница 157: ...Chapter 8 Interface ZyWALL USG 50 H User s Guide 157 Figure 129 Network Interface Ethernet Edit lan1...
Страница 208: ...Chapter 8 Interface ZyWALL USG 50 H User s Guide 208 Figure 161 Network Interface Bridge Add...
Страница 224: ...Chapter 9 Trunks ZyWALL USG 50 H User s Guide 224...
Страница 250: ...Chapter 12 Zones ZyWALL USG 50 H User s Guide 250...
Страница 280: ...Chapter 16 ALG ZyWALL USG 50 H User s Guide 280...
Страница 286: ...Chapter 17 IP MAC Binding ZyWALL USG 50 H User s Guide 286...
Страница 287: ...287 PART III Firewall Firewall 289...
Страница 288: ...288...
Страница 304: ...Chapter 18 Firewall ZyWALL USG 50 H User s Guide 304...
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Страница 313: ...Chapter 19 IPSec VPN ZyWALL USG 50 H User s Guide 313 Figure 238 VPN IPSec VPN VPN Connection Edit IKE...
Страница 356: ...Chapter 21 SSL User Screens ZyWALL USG 50 H User s Guide 356...
Страница 358: ...Chapter 22 SSL User Application Screens ZyWALL USG 50 H User s Guide 358...
Страница 368: ...Chapter 24 L2TP VPN ZyWALL USG 50 H User s Guide 368...
Страница 394: ...Chapter 25 L2TP VPN Example ZyWALL USG 50 H User s Guide 394...
Страница 395: ...395 PART V Application Patrol Application Patrol BWM 397...
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Страница 421: ...421 PART VI Anti X ADP 423...
Страница 422: ...422...
Страница 429: ...Chapter 27 ADP ZyWALL USG 50 H User s Guide 429 Figure 359 Profiles Traffic Anomaly...
Страница 432: ...Chapter 27 ADP ZyWALL USG 50 H User s Guide 432 Figure 360 Profiles Protocol Anomaly...
Страница 440: ...Chapter 27 ADP ZyWALL USG 50 H User s Guide 440...
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Страница 462: ...Chapter 29 Addresses ZyWALL USG 50 H User s Guide 462...
Страница 474: ...Chapter 31 Schedules ZyWALL USG 50 H User s Guide 474...
Страница 484: ...Chapter 32 AAA Server ZyWALL USG 50 H User s Guide 484...
Страница 506: ...Chapter 34 Certificates ZyWALL USG 50 H User s Guide 506...
Страница 510: ...Chapter 35 SSL Application ZyWALL USG 50 H User s Guide 510...
Страница 511: ...511 PART VIII System System 513...
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Страница 568: ...Chapter 38 Logs ZyWALL USG 50 H User s Guide 568 Figure 464 Maintenance Log Log Setting Edit System Log...
Страница 584: ...Chapter 40 Diagnostics ZyWALL USG 50 H User s Guide 584...
Страница 586: ...Chapter 41 Reboot ZyWALL USG 50 H User s Guide 586...
Страница 596: ...Chapter 43 Product Specifications ZyWALL USG 50 H User s Guide 596...
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Страница 636: ...Appendix A Log Descriptions ZyWALL USG 50 H User s Guide 636...
Страница 640: ...Appendix B Common Services ZyWALL USG 50 H User s Guide 640...
Страница 646: ...Appendix C Importing Certificates ZyWALL USG 50 H User s Guide 646...