Advanced Settings; Ip Level Settings - D-Link NetDefend DFL-210 User Manual

Chapter 13. Advanced Settings
This chapter describes the configurable advanced settings for NetDefendOS. The settings are
divided up into the following categories:
• IP Level Settings, page 427
• TCP Level Settings, page 431
• ICMP Level Settings, page 436
• State Settings, page 437
• Connection Timeout Settings, page 439
• Length Limit Settings, page 441
• Fragmentation Settings, page 443
• Local Fragment Reassembly Settings, page 447
• Miscellaneous Settings, page 448

13.1. IP Level Settings

Log Checksum Errors
Logs occurrences of IP packets containing erroneous checksums. Normally, this is the result of the
packet being damaged during network transport. All network units, both routers and workstations,
drop IP packets that contain checksum errors. However, it is highly unlikely for an attack to be
based on illegal checksums.
Default: Enabled
Log non IP4
Logs occurrences of IP packets that are not version 4. NetDefendOS only accepts version 4 IP
packets; everything else is discarded.
Default: Enabled
Log Received TTL 0
Logs occurrences of IP packets received with the "Time To Live" (TTL) value set to zero. Under no
circumstances should any network unit send packets with a TTL of 0.
Default: Enabled
Block 0000 Src
Note: Activate after changes
After an advanced setting is changed an activate operation must be performed in order
for the new NetDefendOS configuration to take effect.
427