FIREWALL

Firewall device is use protect from unauthorized person and security threat, its placed between inside and outside network, Firewall work on Layer 3, Layer 4 & Layer 7.

Types of Firewall-

Packet Filter Firewall-

Its filter packet bases on IP address and Port number.

It defense against DoS & IP spoofing attack.

Circuit level Gateway Firewall- 

Its operate at Transport layer, which can be reassemble or block unwanted packet.

Its also use in VPN over public internet by doing encrypted packet between two peer.

Application level Firewall- 

Its also called “Proxy Firewall” & it function at application level.

We can block malicious and control incoming or outgoing traffic

.

It can protection against virus or span & also provide very complex protection against huge range of threat.

Hybrid Firewall- 

It combination of Application Firewall with other firewall

i.e Application firewall combine with Packet filter firewall or Application firewall combine with circuit level firewall.

Statefull Firewall- 

In this firewall packet is legitimate session within a Inside network.

It maintain information of user connection, IP address, Port number and sequence nos of packet.

Stateless Firewall- 

Its just opposite of Statefull firewall, its does not maintain user information, IP address, Port nos and sequence nos of packet.

It enhance security through packet filter firewall.

Transparent Firewall-

Its work on Layer-2 & it deloy on existing network.

It also insert in existing segment & control traffic between two network.