Home Theater Server User Manual
Table Of Contents
- Contents
- About This Document
- Network Security
- TCP SYN attacks
- IP TCP syn-proxy
- Granular application of syn-proxy feature
- Syn-def
- No response to non-SYN first packet of a TCP flow
- Prioritizing management traffic
- Peak BP utilization with TRAP
- Transaction Rate Limit (TRL)
- Understanding transaction rate limit
- Configuring transaction rate limit
- Configuring the maximum number of rules
- Saving a TRL configuration
- Transaction rate limit command reference
- Global TRL
- TRL plus security ACL-ID
- security acl-id
- Transaction rate limit hold-down value
- Displaying TRL rules statistics
- Displaying TRL rules in a policy
- Displaying IP address with held down traffic
- Refusing new connections from a specified IP address
- HTTP TRL
- Overview of HTTP TRL
- Configuring HTTP TRL
- Displaying HTTP TRL
- Display all HTTP TRL policies
- Display HTTP TRL policy from index
- Display HTTP TRL policy client
- Display HTTP TRL policy starting from index
- Display HTTP TRL policy matching a regular expression
- Display HTTP TRL policy client index (MP)
- Display HTTP TRL policy client index (BP)
- Display HTTP TRL policy for all client entries (BP)
- Downloading an HTTP TRL policy through TFTP
- HTTP TRL policy commands
- Logging for DoS Attacks
- Maximum connections
- clear statistics dos-attack
- Maximum concurrent connection limit per client
- Firewall load balancing enhancements
- Syn-cookie threshhold trap
- Service port attack protection in hardware
- Traffic segmentation
- DNS attack protection
- Access Control List
- How ServerIron processes ACLs
- Default ACL action
- Types of IP ACLs
- ACL IDs and entries
- ACL entries and the Layer 4 CAM
- Configuring numbered and named ACLs
- Modifying ACLs
- Displaying a list of ACL entries
- Applying an ACLs to interfaces
- ACL logging
- Dropping all fragments that exactly match a flow-based ACL
- Enabling ACL filtering of fragmented packets
- Enabling hardware filtering for packets denied by flow-based ACLs
- Enabling strict TCP or UDP mode for flow-based ACLs
- ACLs and ICMP
- Using ACLs and NAT on the same interface (flow-based ACLs)
- Displaying ACL bindings
- Troubleshooting rule-based ACLs
- IPv6 Access Control Lists
- Network Address Translation
- Syn-Proxy and DoS Protection
- Understanding Syn-Proxy
- Configuring Syn-Proxy
- DDoS protection
- Configuring a security filter
- Configuring a Generic Rule
- Configuring a rule for common attack types
- Configuring a rule for ip-option attack types
- Configuring a rule for icmp-type options
- Configuring a rule for IPv6 ICMP types
- Configuring a rule for IPv6 ext header types
- Binding the filter to an interface
- Clearing DOS attack statistics
- Clearing all DDOS Filter & Attack Counters
- Logging for DoS attacks
- Displaying security filter statistics
- Address-sweep and port-scan logging
- Secure Socket Layer (SSL) Acceleration
- SSL overview
- SSL acceleration on the ServerIron ADX
- Configuring SSL on a ServerIron ADX
- Basic SSL profile configuration
- Advanced SSL profile configuration
- Configuring Real and Virtual Servers for SSL Termination and Proxy Mode
- Configuration Examples for SSL Termination and Proxy Modes
- SSL debug and troubleshooting commands
- Displaying socket information
ServerIron ADX Security Guide 3
53-1002440-03
Syn-def
1
The last line contains information relevant to the incomplete connection threshold. The TCP
SYN-DEF RST field displays the number of times the incomplete connection threshold was reached.
The Server Resets field displays the number of times the ServerIron sent a TCP RESET packet to
the destination real server.
SYN-def-dont-send-ack
The SYN-def feature allows the ServerIron to complete the TCP three-way handshake on behalf of a
connecting client. When a connecting client sends a TCP SYN to a server, the ServerIron forwards
the SYN to the real server, then forwards the SYN ACK from the server to the client. Next, the
ServerIron sends an ACK to the real server, completing the three-way handshake on behalf of the
connecting client. This action allows the real server to move the connection from its pending
connection queue to its established (and much larger) connection queue.
Use the server syn-def-dont-send-ack command to prevent the ServerIron from sending the ACK to
the real server to complete the three-way handshake.
Example
ServerIronADX(config)#server syn-def-dont-send-ack
show server debug
Use the show server debug command to display information about the configuration, as shown in
the following example.
ServerIronADX# show server traffic
Client->Server = 0 Server->Client = 0
Drops = 0 Aged = 0
Fw_drops = 0 Rev_drops = 0
FIN_or_RST = 0 old-conn = 0
Disable_drop = 0 Exceed_drop = 0
Stale_drop = 0 Unsuccessful = 0
TCP SYN-DEF RST = 0 Server Resets = 0
Out of Memory = 0 Out of Memory = 0