The best way to automate a firewall policy using a daily updated list of IP addresses is by using an external connector from Threat Feeds. This allows FortiGate to dynamically retrieve real-time threat intelligence from external sources and apply it directly to security policies.
By configuring Threat Feeds, the administrator can:
# Automatically update firewall policies with the latest malicious IPs daily.
# Block traffic from those IPs in real-time without manual intervention.
# Integrate with FortiGuard, third-party threat intelligence sources, or custom feeds (CSV, STIX/TAXII, etc.).

The TCP Maximum Segment Size (MSS) defines the largest payload (the data part of a TCP segment) that a device can receive in a single segment. Configuring tcp-mss-sender and tcp-mss-receiver on a FortiGate interface or within an IPsec tunnel configuration allows the firewall to intercept and modify the MSS value in the TCP SYN and SYN-ACK packets. This is primarily used to prevent packet fragmentation over links with lower MTUs (like IPsec or VXLAN) by ensuring the sender produces segments that fit within the tunnel ' s available payload space once encapsulation headers are added.
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From the exhibit, ISFW is part of a Security Fabric environment with NGFW-1 as the Fabric Root. In this architecture, FortiGate devices share security intelligence, including logs and detected threats.
ISFW is in a Security Fabric environment:
# Security Fabric allows devices like ISFW to receive threat intelligence from NGFW-1, even if UTM is not enabled locally.
# If NGFW-1 detects malware from IP 10.1.10.1 to 89.238.73.97, this information can be propagated to ISFW and FortiAnalyzer.
The firewall policy in NGFW-1 has UTM enabled:
# Even though ISFW does not have UTM enabled, NGFW-1 (which sits between ISFW and the external network) does have UTM enabled and is scanning traffic.
# Since NGFW-1 detects malware in the session, it logs the event, which is then sent to FortiAnalyzer.

FortiGate, like other security appliances, cannot analyze encrypted HTTPS traffic unless it decrypts it first. If only certificate inspection is enabled, FortiGate can see the certificate details (such as the domain and issuer) but cannot inspect the actual web content.
To fully analyze the traffic and detect potential malware threats:
# Full SSL inspection (Deep Packet Inspection) must be enabled in the SSL/SSH Inspection Profile.
# This allows FortiGate to decrypt the HTTPS traffic, inspect the content, and then re-encrypt it before forwarding it to the user.
# Without full SSL inspection, threats embedded in encrypted traffic may go undetected.

The best way to block outdated SSL/TLS versions is to configure the SSL/SSH inspection profile to enforce a minimum SSL/TLS version and disable weak SSL versions.
By setting the minimum allowed SSL version in the HTTPS settings of the SSL/SSH inspection profile, FortiGate will:
# Block any connection using outdated SSL/TLS versions (such as SSLv3, TLS 1.0, or TLS 1.1).
# Enforce secure communication using only strong SSL/TLS versions (such as TLS 1.2 or TLS 1.3).
# Protect users from man-in-the-middle (MITM) and downgrade attacks that exploit weak encryption.