06Stateless versus stateful firewalls, NAT, and egress filtering: what does each actually protect?▼easyNewCiscoPalo Alto NetworksCheck Point○ sign inNAT is not a firewall, and inbound rules are only half a policy. Interviewers check whether you know what each device decides, and why the outbound direction is where breaches are contained.Open full answer →
19How does NAT actually work, how do peers get through it, and why is 'we are behind NAT' not a security control?▼mediumNewGoogleMicrosoftCisco◆ premiumNAT drops unsolicited inbound packets as a side effect of bookkeeping, not policy. Port forwards, UPnP, outbound connections and IPv6 all walk around it.Open full answer →
20How do firewalls work underneath: stateless vs stateful filtering, connection tracking, the netfilter path, and failing rule sets?▼mediumNewPalo Alto NetworksCheck PointCisco◆ premiumA firewall is a list of match conditions evaluated in order against fields it can see, plus a table that remembers connections. Almost every firewall failure is in one of those three words: order, fields, remember.Open full answer →
30How do attackers compromise routers, firewalls and VPN appliances, and how would you harden and monitor them?▼mediumNewPalo Alto NetworksCiscoCrowdStrike◆ premiumThe device that guards the network is itself a server on the internet, often unmonitored and rarely patched. Interviewers want to hear how you would treat it like one.Open full answer →