Chapter 11 Firewall screens
171
Nortel Business Secure Router 252 Configuration — Basics
Rule logic overview
Rule checklist
1
State the intent of the rule. For example, “This restricts all IRC access from
the LAN to the Internet.” Or, “This allows a remote Lotus Notes server to
synchronize over the Internet to an inside Notes server.”
2
Is the intent of the rule to forward or block traffic?
3
What direction of traffic does the rule apply to?
4
What IP services are affected?
5
What computers on the LAN are affected (if any)?
6
What computers on the Internet are affected? The more specific, the better.
For example, if traffic is allowed from the Internet to the LAN, it is better to
allow only certain machines on the Internet to access the LAN.
Security ramifications
Once the logic of the rule has been defined, it is critical to consider the security
ramifications created by the rule:
1
Does this rule stop LAN users from accessing critical resources on the
Internet? For example, if IRC is blocked, are there users that require this
service?
2
Is it possible to modify the rule to be more specific? For example, if IRC is
blocked for all users, a rule that blocks just certain users can be more
effective.
3
Does a rule that allows Internet users access to resources on the LAN create a
security vulnerability? For example, if FTP ports (TCP 20, 21) are allowed
from the Internet to the LAN, Internet users can connect to computers with
running FTP servers.
4
Does this rule conflict with any existing rules?
Note:
Study these points carefully before configuring rules.
Summary of Contents for BSR252
Page 28: ...28 Tables NN47923 500 ...
Page 44: ...44 Chapter 1 Getting to know your Business Secure Router NN47923 500 ...
Page 52: ...52 Chapter 2 Introducing the WebGUI NN47923 500 ...
Page 70: ...70 Chapter 3 Wizard setup NN47923 500 ...
Page 96: ...96 Chapter 5 System screens NN47923 500 ...
Page 114: ...114 Chapter 7 WAN screens NN47923 500 Figure 27 WAN IP ...
Page 120: ...120 Chapter 7 WAN screens NN47923 500 Figure 31 Dial Backup Setup ...
Page 128: ...128 Chapter 7 WAN screens NN47923 500 ...
Page 152: ...152 Chapter 9 Static Route screens NN47923 500 ...
Page 194: ...194 Chapter 11 Firewall screens NN47923 500 ...
Page 210: ...210 Chapter 13 VPN NN47923 500 Figure 67 Summary IP Policies ...
Page 222: ...222 Chapter 13 VPN NN47923 500 Figure 71 VPN Branch Office rule setup ...
Page 256: ...256 Chapter 13 VPN NN47923 500 Figure 81 VPN Client Termination advanced ...
Page 260: ...260 Chapter 13 VPN NN47923 500 ...
Page 264: ...264 Chapter 14 Certificates NN47923 500 Figure 83 My Certificates ...
Page 270: ...270 Chapter 14 Certificates NN47923 500 Figure 85 My Certificate create ...
Page 274: ...274 Chapter 14 Certificates NN47923 500 Figure 86 My Certificate details ...
Page 282: ...282 Chapter 14 Certificates NN47923 500 Figure 89 Trusted CA details ...
Page 298: ...298 Chapter 14 Certificates NN47923 500 ...
Page 316: ...316 Chapter 16 IEEE 802 1x NN47923 500 ...
Page 320: ...320 Chapter 17 Authentication server NN47923 500 Figure 106 Local User database edit ...
Page 328: ...328 Chapter 17 Authentication server NN47923 500 ...
Page 376: ...376 Chapter 20 Logs Screens NN47923 500 Figure 150 Log settings ...
Page 386: ...386 Chapter 20 Logs Screens NN47923 500 ...
Page 393: ...Chapter 21 Call scheduling screens 393 Nortel Business Secure Router 252 Configuration Basics ...
Page 394: ...394 Chapter 21 Call scheduling screens NN47923 500 ...
Page 410: ...410 Chapter 22 Maintenance NN47923 500 ...