Prestige 661H/HW Series User’s Guide
Chapter 11 Firewalls
136
All SMTP commands are illegal except for those displayed in the following tables.
11.4.2.3 Traceroute
Traceroute is a utility used to determine the path a packet takes between two endpoints.
Sometimes when a packet filter firewall is configured incorrectly an attacker can traceroute
the firewall gaining knowledge of the network topology inside the firewall.
Often, many DoS attacks also employ a technique known as "
IP Spoofing
" as part of their
attack. IP Spoofing may be used to break into systems, to hide the hacker's identity, or to
magnify the effect of the DoS attack. IP Spoofing is a technique used to gain unauthorized
access to computers by tricking a router or firewall into thinking that the communications are
coming from within the trusted network. To engage in IP spoofing, a hacker must modify the
packet headers so that it appears that the packets originate from a trusted host and should be
allowed through the router or firewall. The Prestige blocks all IP Spoofing attempts.
11.5 Stateful Inspection
With stateful inspection, fields of the packets are compared to packets that are already known
to be trusted. For example, if you access some outside service, the proxy server remembers
things about your original request, like the port number and source and destination addresses.
This “remembering” is called
saving the state.
When the outside system responds to your
request, the firewall compares the received packets with the saved state to determine if they
are allowed in. The Prestige uses stateful packet inspection to protect the private LAN from
hackers and vandals on the Internet. By default, the Prestige’s stateful inspection allows all
communications to the Internet that originate from the LAN, and blocks all traffic to the LAN
that originates from the Internet. In summary, stateful inspection:
• Allows all sessions originating from the LAN (local network) to the WAN (Internet).
• Denies all sessions originating from the WAN to the LAN.
RETARGET:
KEEPALIVE:
Table 39
Legal SMTP Commands
AUTH
DATA
EHLO
ETRN
EXPN
HELO
HELP
NOOP
QUIT
RCPT
RSET
SAML
SEND
SOML
TURN
VRFY
Table 38
Legal NetBIOS Commands
Содержание Prestige 661H Series
Страница 37: ...Prestige 661H HW Series User s Guide 37 List of Tables...
Страница 41: ...Prestige 661H HW Series User s Guide 41 Introduction to DSL...
Страница 51: ...Prestige 661H HW Series User s Guide 51 Chapter 1 Getting To Know Your Prestige...
Страница 67: ...Prestige 661H HW Series User s Guide 67 Chapter 3 Wizard Setup for Internet Access...
Страница 81: ...Prestige 661H HW Series User s Guide 81 Chapter 5 LAN Setup...
Страница 125: ...Prestige 661H HW Series User s Guide 125 Chapter 8 Network Address Translation NAT Screens...
Страница 143: ...Prestige 661H HW Series User s Guide 143 Chapter 11 Firewalls...
Страница 151: ...Prestige 661H HW Series User s Guide 151 Chapter 12 Firewall Configuration Figure 64 Firewall Edit Rule...
Страница 165: ...Prestige 661H HW Series User s Guide 165 Chapter 12 Firewall Configuration...
Страница 169: ...Prestige 661H HW Series User s Guide 169 Chapter 13 Content Filtering...
Страница 175: ...Prestige 661H HW Series User s Guide 175 Chapter 14 Introduction to IPSec...
Страница 203: ...Prestige 661H HW Series User s Guide 203 Chapter 15 VPN Screens...
Страница 207: ...Prestige 661H HW Series User s Guide 207 Chapter 16 Remote Management Configuration...
Страница 221: ...Prestige 661H HW Series User s Guide 221 Chapter 17 Universal Plug and Play UPnP...
Страница 227: ...Prestige 661H HW Series User s Guide 227 Chapter 18 Logs Screens...
Страница 241: ...Prestige 661H HW Series User s Guide 241 Chapter 19 Media Bandwidth Management Advanced Setup...
Страница 265: ...Prestige 661H HW Series User s Guide 265 Chapter 21 Maintenance...
Страница 275: ...Prestige 661H HW Series User s Guide 275 Chapter 23 Menu 1 General Setup...
Страница 279: ...Prestige 661H HW Series User s Guide 279 Chapter 24 Menu 2 WAN Backup Setup...
Страница 283: ...Prestige 661H HW Series User s Guide 283 Chapter 25 Menu 3 LAN Setup...
Страница 287: ...Prestige 661H HW Series User s Guide 287 Chapter 26 Wireless LAN Setup...
Страница 293: ...Prestige 661H HW Series User s Guide 293 Chapter 27 Internet Access...
Страница 307: ...Prestige 661H HW Series User s Guide 307 Chapter 29 Static Route Setup...
Страница 311: ...Prestige 661H HW Series User s Guide 311 Chapter 30 Bridging Setup...
Страница 327: ...Prestige 661H HW Series User s Guide 327 Chapter 31 Network Address Translation NAT...
Страница 343: ...Prestige 661H HW Series User s Guide 343 Chapter 33 Filter Configuration...
Страница 363: ...Prestige 661H HW Series User s Guide 363 Chapter 36 System Information and Diagnosis...
Страница 375: ...Prestige 661H HW Series User s Guide 375 Chapter 37 Firmware and Configuration File Maintenance...
Страница 381: ...Prestige 661H HW Series User s Guide 381 Chapter 38 System Maintenance...
Страница 385: ...Prestige 661H HW Series User s Guide 385 Chapter 39 Remote Management...
Страница 395: ...Prestige 661H HW Series User s Guide 395 Chapter 40 IP Policy Routing...
Страница 399: ...Prestige 661H HW Series User s Guide 399 Chapter 41 Call Scheduling...
Страница 411: ...Prestige 661H HW Series User s Guide 411 Chapter 42 VPN IPSec Setup...
Страница 415: ...Prestige 661H HW Series User s Guide 415 Chapter 43 SA Monitor...
Страница 427: ...Prestige 661H HW Series User s Guide 427 Chapter 44 Troubleshooting Figure 275 Security Setting ActiveX Controls...
Страница 431: ...Prestige 661H HW Series User s Guide 431 Appendix A...
Страница 451: ...Prestige 661H HW Series User s Guide 451 Appendix C IP Subnetting...
Страница 455: ...Prestige 661H HW Series User s Guide 455 Appendix E Command Interpreter...
Страница 461: ...Prestige 661H HW Series User s Guide 461 Appendix F Firewall Commands...
Страница 464: ...Prestige 661H HW Series User s Guide Appendix G NetBIOS Filter Commands 464...
Страница 465: ...Prestige 661H HW Series User s Guide 465 Appendix G NetBIOS Filter Commands...
Страница 478: ...Prestige 661H HW Series User s Guide Appendix H VPN Setup 478 ftp 5631148 bytes sent in 614 8Seconds 9 17Kbytes sec...
Страница 479: ...Prestige 661H HW Series User s Guide 479 Appendix H VPN Setup...
Страница 482: ...Prestige 661H HW Series User s Guide Appendix I Splitters and Microfilters 482...
Страница 483: ...Prestige 661H HW Series User s Guide 483 Appendix I Splitters and Microfilters...
Страница 537: ...Prestige 661H HW Series User s Guide 537 Appendix M Internal SPTGEN...