Got an IT interview coming up? Don’t just memories commands—know what’s happening behind them. 

1. What is a firewall policy?
A rule that allows or denies matching traffic based on interfaces, addresses, services and schedules.

2. SNAT vs DNAT?
SNAT changes the source IP, commonly for Internet access. DNAT changes the destination IP, commonly to reach an internal server.

3. No Internet access?
Check the client’s IP, gateway and DNS. Then check interfaces, routing, firewall policies, NAT and logs.

4. Policy-based vs route-based VPN?
Policy-based VPN selects traffic through an IPsec firewall policy. Route-based VPN uses a tunnel interface and routing, with firewall policies permitting traffic.

5. Policy looks fine, but traffic still fails?
Verify the actual policy match, NAT, security profiles, sessions and return path. Let logs and packet captures do the talking.


Interview tip: Explain why you’re checking something. Random commands won’t carry the interview.

More practical IT knowledge at alknetwork.com.