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- Table of Contents
-
- 09-Security Command Reference
- 00-Preface
- 01-AAA commands
- 02-802.1X commands
- 03-MAC authentication commands
- 04-Portal commands
- 05-Web authentication commands
- 06-Port security commands
- 07-User profile commands
- 08-Password control commands
- 09-Keychain commands
- 10-Public key management commands
- 11-IPsec commands
- 12-SSH commands
- 13-SSL commands
- 14-TCP attack prevention commands
- 15-IP source guard commands
- 16-ARP attack protection commands
- 17-ND attack defense commands
- 18-SAVI commands
- 19-MFF commands
- 20-Crypto engine commands
- 21-FIPS commands
- 22-802.1X client commands
- 23-Attack detection and prevention commands
- Related Documents
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| Title | Size | Download |
|---|---|---|
| 23-Attack detection and prevention commands | 40.05 KB |
Attack detection and prevention commands
attack-defense tcp fragment enable
Use attack-defense tcp fragment enable to enable TCP fragment attack prevention.
Use undo attack-defense tcp fragment enable to disable TCP fragment attack prevention.
Syntax
attack-defense tcp fragment enable
undo attack-defense tcp fragment enable
Default
TCP fragment attack prevention is enabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
This command enables the device to drop attack TCP fragments to prevent TCP fragment attacks that the packet filter cannot detect. As defined in RFC 1858, attack TCP fragments refer to the following TCP fragments:
· First fragments in which the TCP header is smaller than 20 bytes.
· Non-first fragments with a fragment offset of 8 bytes (FO=1).
TCP fragment attack prevention takes precedence over single-packet attack prevention. When both are used, incoming TCP packets are processed first by TCP fragment attack prevention and then by the single-packet attack defense policy.
Examples
# Enable TCP fragment attack prevention.
<Sysname> System-view
[Sysname] attack-defense tcp fragment enable
