All internal IP address to the outside person is covert. Because of this reason, outside the network nobody may through assign the IP address the way to initiate the attack directly to network any specific computer.
Because if some kind of reason public IP address resources are quite short, NAT may cause the entire internal network to share a IP address.
May begin using the basic package filtration firewall safety mechanism, because all spreads if the package does not have to assign to dispose NAT specially, will then be discarded. The internal network's computer is impossible to visit the exterior network directly.
Uses NAT the shortcoming:
The NAT shortcoming and the package filter firewall's shortcoming are the same. Although may safeguard the internal network the security, but it is also some similar limitations. Moreover in the net may use presently spreads the quite widespread wooden horse procedure to be possible to make the exterior connection through NAT, looks like it to be possible to pass through package of filtration firewall same easy.
Attention: Now has many manufacturer development firewall, specially the condition/dynamic examination firewall, the function which should have besides them also has provided the NAT function.
5. individual firewall
Individual firewall's merit includes:
Increased the protection rank, does not need the extra hardware source.
Individual firewall except may resist the external attack at the same time, but may also resist the internal attack.
Individual firewall has provided the protection to the public network single system. What for example a family user use is Modem or ISDN/ADSL accesses the net, the possible hardware firewall regarding him is really too expensive, or was too troublesome. But individual firewall already could expose for the user hiding in the network the information, for instance IP address and so on information and so on.
Individual firewall's shortcoming:
The individual firewall main shortcoming has a physical interface to the public network. Must remember, the genuine firewall must monitor and control two
Or between more network interface correspondence. Words as the matter stands, individual firewall itself possibly easy to be threaten, or will be has this kind of weakness, the network service may bypass firewall's rule.
Good, we already introduced in above several kind of firewalls, and discussed each kind of firewall's good and bad points. Must remember, any kind of firewall was only or is the data transmission provides for the network service had the safeguard security, but we could not the total dependence in the firewall. Except depends on the firewall to safeguard the security at the same time, we must reinforce system's security, raises own safety consciousness. As the matter stands, the data and the correspondence as well as the Web stand will have the safety control.
Other pages: : <<Prev * 1 * 2 * 3 * 4 * 5 * 6 * 7
|
You are here: hacking technology
> firewall
> Content
Category: Home
> firewall