SNA IP TABLE AND FILTERING 34562489.pptx

SNA IP TABLE AND FILTERING 34562489.pptx

1. Firewall: “A firewall is a network security tools that monitors incoming and outgoing network traffic and permits or blocks data packet based on predefined set of security rules . Firewalls can be hardware or software implementation” Available Firewalls: Cisco ASA(adaptive security appliance) Checkpoint Firewall/Hardware Firewall Microsoft ISA Linux based Net Filter Iptable Firewall

2. Iptables: Actually, iptables is a user level program that control the kernel-level network module is called Net-filter.

3. Advantage of Ip-table firewall: In linux “ iptables”perform the function of the firewall . Open source Low cost (or you can say no cost at all) Highly flexible stateful firewall

4. Ip table filter packet based on: The function of iptables tool is packet filtering . The packet filtering mechanism is organized into three different kinds of structure : Tables Chain Target

5. Types of Table Firewalls: Filter Firewalls: “Firewalls are appliances that protect networks against external intrusion by screening incoming data and admitting or excluding traffic” ‘’This table is in charge of filtering packet’’ Network Address Translation  (NAT) ‘’This table is charge of translating Ip addresses of the packet’’ The Two main NAT types are : (SNAT) Source network address Translation (DNAT) Destination network address Translation MANGLE‘’ “This tables is in charge of changing packet content’’ Raw Table “Used for connection tracking”

6. SNAT:  Source network address translation named as (Source- Nat or Snat ) Allow traffic from a private network to go out the internet.

7. (DNAT) “Destination NAT is performed on incoming packets when the firewall translates a destination address to a different destination address; for example, it translates a public destination address to a private destination address”