Second generation firewalls are able to recognise whether the incoming packet is a part of an existing connection or the beginning of the new one. the second generation of firewalls, inspect packets on transport layers and keep track of the connection state (stateful inspection) unless they gain sufficient amount of information. In order for the firewall to recognise a harmful packet content, it must be able to search for the associations between individual packets. Another problem is the fact that origin of the packet might be falsified easily. on the receiver’s part that is why the firewall investigating only the control information (otherwise source and target) can hardly discover whether or not does the message contain any threats. Hence a complete message is assembled in the final destination, i.e.

Nonetheless, data for transfer are segmented into smaller parts, so-called packets, of which each and every one bears in itself only a piece of information about the character of the data. Firewall thus blocks the traffic based on the fact from which node and/or network it is coming from. Target IP addresses and ports are controlled on the network level. Older firewall versions control solely traffic source and its target. Source: networkhope.in Firewalls Based on the Ways of Traffic Filtration Reference model ISO/OSI, an illustration of communication solution in computer and telecommunication networks using multi-level model. Firewalls differ from each other particularly in the level on which the traffic is filtered. Each level has its functions necessary for communication clearly defined. It is just the means by which individual firewalls decide on non/safety of certain traffic that draws the line between them.Ī reference model of seven-level architecture might come in handy when illustrating computer and telecommunication networks. When filtering, a check on traffic is conducted and the decision whether to let it into a protected network is made.

Firewalls separate those safely and facilitates filtration of all the traffic flowing into the secured network. It is useful at any internet communication involving two networks with different level of security and reliability.

Firewall is an inseparable part both of company IT and personal computers.

Winbox firewall