Research of the IP-Telephony for the Czech Armed Forces Zburníková Lucie Lt. Bc. Zburníková Lucie

Main points of presentation characteristic of IP-telephony aims of the scientific work DoS attacks prevention and response overall summary 2

3 Aims of the scientific work to create a possible network diagram to categorize the DoS attacks to make the total and actual list of them to make the total and actual list of them to propose the form of detection and counteraction against them

Network diagram 4

5 Categories and types of Denial of Service attacks Direct Denial of Service attacks: Direct Denial of Service attacks: Single-tier attacks Single-tier attacks Dual-tier attacks Dual-tier attacks Triple-tier ‘distributed’ attacks Triple-tier ‘distributed’ attacks Indirect Denial of Service attacks: Indirect Denial of Service attacks: The LoveBug virus The LoveBug virus Code Red and Nimda worms Code Red and Nimda worms

6 Direct Denial of Service attacks  Single-tier DoS Attacks ( ) Examples: Ping of Death, SYN floods, other malformed packet attacks  Dual-tier DoS Attacks (late 1997)‏ Example: Smurf  Triple-tier DDoS Attacks ( )‏ Examples: TFN2K, Stacheldraht, Mstream

7 Compare of the attacks  Older attacks are ineffective or of low danger.  The attempts that use new vulnerabilities of systems have low lifetime.  Flood attacks are simple, but dangerous.  DDoS flood attacks cause serious problems which can shift of any server.  Some new attempts can combine number of different simple attacks and can use DDos.

8 Prevention and Response Intrusion detection system (IDS) Intrusion detection system (IDS) network intrusion detection system network intrusion detection system protocol-based intrusion detection system (Example: Snort)‏ protocol-based intrusion detection system (Example: Snort)‏ application protocol-based intrusion detection system application protocol-based intrusion detection system host-based intrusion detection system host-based intrusion detection system hybrid intrusion detection system (Example: Prelude)‏ hybrid intrusion detection system (Example: Prelude)‏ Intrusion prevention system Intrusion prevention system (Self)defence against DoS attacks (Self)defence against DoS attacks

- Network -Based Host- Based + It's able to verify if attack was succesful or not. The functionality isn't affected by transmission or using the encryption. It's able to prevent the attack. It uses server as a source. The possibility of usage depends on OS. The extensibility - requires installation of one agent / server. It protects all terminal station on the monitoring net. It has no influence on function of the terminal stations / servers. It's able to detect DoS attacks. There are more difficult implement. in the environment of the switching LAN. Monitoring above 1Gb/s is the problem for now. Generally it can't for-actively stop the attack. Network-based vs. host- based system

10 Solution Set Router Sensor Host Sensor Firewall Sensor Mgmt Network Sensor Standard Edition Web Server Edition xxx Secure Command Line Web UI Embedded Mgr CiscoWorks VMS Switch Sensor Catalyst 6500 IDS Module E515E IDS on platforms of Cisco

11 General defence The systems for detection (and prevention) unauthorized intersection get past accessories for security nets by the firewalls. We obtain high level of defence in the face of unauthorized activities by the combination of net IDS and IDS for servers. The correct function of IDS has to be supported by regular plotting the adventitious information and upgrade of the system.

Overall summary VoIP telephony has a great potential to bring considerable advantages into telecommunications in comparison with standard technologies. The main advantage is cost reduction especially in the case of long distance calls. It offers quality phone services including secure voice and development prevention and response. 12