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
180 ServerIron ADX Security Guide
53-1002440-03
Configuration Examples for SSL Termination and Proxy Modes
6
FIGURE 16 Server Capture
In these examples, the HTTP GET requests are intentionally broken down into multiple parts. In real
life, you may not see GET requests divided over multiple packets.
These trace results indicate that there is degradation of performance when the ServerIronADX is
configured for SSL terminate. According to the client trace, packets 1- 10 are all handshake
messages and packets 11,13,15,17,19,21,23 are separate records, each having a small part of
the GET request, which immediately receives an ACK.
The problem in this case is on the server side. The Microsoft 2003 server has delayed ACK ON
enabled, and the delayed ACK timer is set for 200 ms. Since the Nagle Algorithm is ON by default,
the ServerIronADX will not send the next packet as long as there is unacknowledged data. As
shown in the server side trace, the first data that is sent to the server is the partial GET request.
The complete GET request has 6 more parts. Packet number 4 is the partial GET, for which you see
an ACK in packet 5.
Packet 4, length 71, (frame-size) is not a full-sized packet, so the server waits for more data
packets, since it has advertised a greater window size. Because the Nagle Algorithm is enabled, the
ServerIronADX does not send any more data and the server only sends an ACK after 200 ms
(packet #5). The ServerIronADX waits to receive this ACK, and then sends the subsequent data
packet. This process continues, and all seven packets are delayed by 200 ms resulting in total
delay of 1.4 seconds, which results in the slow response time.