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To avoid 65K+ lines of mostly-useless output, Nmap collapses most "uninteresting" results into a line that says something like "Not shown: 65530 filtered ports." Open ports are never collapsed this way, but closed (TCP RST) and filtered (no response or ICMP admin-prohibited) ports are only shown if there are fewer than a certain number. In your case, I ...


Simply, a DMZ is portion of your network carved off and isolated from the rest of your network. A firewall is the appliance that creates that isolation, by restricting traffic both between the intranet and the DMZ and the DMZ and other networks it's exposed to.


Advanced Persistent Threats (APT) describes actual threats. Depending on who you talk to and the context these are sophisticated and targeted attacks by advanced actors with lots of money like states or criminal organisations - or simply anything which is more complex than what basic firewalls and antivirus products could detect (like in "it wasn't our ...


It is the never ending race between weapons and armors... No firewall can prevent a user to do bad things. Stupidly simple firewalls (only port filtering) will mainly prevent unintentional misuse. Common firewalls (port filtering + HTTP(S) white/black lists will be enough for not too technical attackers. If you want more, you will have to consistently ...


If TLS is being used, does firewall decrypt the traffic before relying it to the client Traditionally, no, for most definitions of "firewall." or does it relay crypted traffic to the client which then somehow decrypts it? It just relays the packets, and the client decrypts. I say "Traditionally" because there are other devices - reverse proxies, load ...


If you use Cisco it might be easier to build a network topology diagram using Cisco Discovery Protocol than firewall rules or ACLs even if manually done.


The source address that you're seeing,, is not a normal IP address, it's an IPv4 Multicast Address. Any one of your internal systems can legitimately try to use it. It's used for trying to join into a stream of traffic that's being sent to multiple recipients - like a television signal that all TVs can tune in to. Your firewall isn't ...


Both are two different concepts. As you mention ACLs(Access Control List) are basically a list of rules for controlling the access to a resource. This can be applied to different network elements or security systems such as Firewalls, IPS, etc.... On the other hand, a state-full firewall is a Firewall (specific security system) that keep tracks of the ...

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