iptables komutu

Firewall Kelimesi Nereden Geliyor
İmalat sanayinden geliyor. Örneğin uçaklarda kullanılan iki tip panel var. Bunlar bulkhead ve firewall. Açıklaması şöyle. Yazılım dünyasında da firewall aynı imalat sanayindeki gibi iki yapıyı birbirinden ayırmak için kullanılıyor.

A bulkhead is any kind of structural panel separating two spaces in a fuselage. Like a solid panel in the tail cone that has only small holes for cables to pass, or the panel that forms the end of the baggage area. Pretty much any solid lateral partition with a structural use. On a large aircraft, any structural partitions separating parts of the cabin, like the flight deck bulkhead, or terminating the pressure hull at each end, the "pressure bulkheads".

A firewall is a firebreak. It's a bulkhead that is fireproof to separate a "hot" area like an engine compartment from adjacent structure, so that if you have an engine fire, you'll have more time to try to land, or if at high altitude, say your prayers. To be a firewall, the material of the bulkhead has to be flame resistant, with a much higher melting point than aluminum.

On GA airplanes, the firewall is usually stainless steel, but can be galvanized steel (antiques and homebuilts), or even special flame proof coatings on a normal bulkhead (some composite homebuilts). On transport airplanes, a firewall will be stainless or titanium.

Demilitarized Zone - DMZ Bölgesi

Demilitarized Zone yazısına taşıdım

Intrusion Detection System 
Intrusion Detection System  (IDS) gibi sistemler iç ağa kurulur ve bu ağdaki tüm bilgisayarları zararlı yazılımlara karşı belli aralıkta tarar.

-L seçeneği - list
Şöyle yaparız.

iptables -L -n

Çıktı olarak şunu alırız. Input, Forward, Output başlıkları görülebilir.

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
...

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
...

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
...

Input başlığı şöyledir.

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
DROP       all  --  151.101.52.0/24      anywhere
REJECT     tcp  --  151.101.52.84        anywhere             ...
DROP       all  --  151.101.52.84        anywhere
DROP       all  --  151.101.52.84        anywhere
DROP       tcp  --  151.101.52.84        anywhere
ACCEPT     tcp  --  anywhere             anywhere             ...

tcpmss modülü
tcpmss yazısına taşıdım.