The most secure and explicit method is to create a custom application for the specific encrypted traffic (HTTPS) you wish to allow, and pair it with a deny policy for the unencrypted equivalent (HTTP). This uses the positive enforcement model (default deny) and provides clear intent. Relying on IPS or AppSecure for the core blocking intent is less direct and can be error-prone, while using ‘application any’ or a combined service set violates the requirement to explicitly block other web traffic.

Excessively long TCP session timeouts are a common cause of artificially inflated session table usage. Idle connections (e.g., from forgotten SSH sessions, old browser tabs) are kept in the table for hours or days, preventing those resources from being reused. While logging or licensing can cause issues, they wouldn’t typically manifest as a persistently high session count. Flow mode is the default and correct mode for most deployments.

Even with matching proxy IDs, Phase 2 (IPsec SA) negotiation can fail if the traffic selectors do not form a compatible pair. For example, if the SRX proposes a selector for 192.168.1.0/24 -> 10.0.0.0/24, the peer must propose a selector that is compatible (e.g., 10.0.0.0/24 -> 192.168.1.0/24) for the reverse traffic. Mismatched or overly restrictive selectors are a frequent cause of Phase 2 failures after Phase 1 succeeds.

Without SSL Proxy, the SRX cannot see the URL inside encrypted HTTPS traffic. The initial TCP/TLS handshake for the social media site succeeds, so the browser begins to load the page. Only after the SSL Proxy decrypts the traffic can the URL filtering policy inspect the hostname or full URL and enforce the block, leading to the described delay. Enabling SSL Proxy (with appropriate certificates) is necessary for instantaneous and effective filtering of modern HTTPS-based social media.

Scheduler-based policing (hierarchical policing) in Junos is applied through firewall filters. The process is: 1) Define a traffic scheduler (e.g., ‘high-priority’) with guaranteed and maximum rates. 2) Create a scheduler map that associates a priority level (e.g., ‘high’) with that scheduler. 3) Create a policer that uses that scheduler map. 4) Apply a firewall filter containing a term that uses the ‘policer’ action for the CEO’s traffic (matched by source IP/DSCP/etc.). The filter is then applied to the ingress interface.

Source NAT pool with address shifting (also called PAT pool or deterministic NAT) provides a one-to-one or predictable mapping between internal and external IPs. This is essential for scenarios where you need to know which internal host (like a DMZ server) used which public IP for outbound connections, for logging, troubleshooting, or meeting compliance requirements where source IP must be traceable. Interface NAT uses overload (PAT) on a single IP, making such tracing difficult or impossible.

Security policies are evaluated from top to bottom. Placing rules for specific, static applications (which are fast to identify) first improves performance. Rules for dynamic application groups, which may require deeper packet inspection (DPI), should come later. This ensures traffic that can be matched early doesn’t incur the processing overhead of DPI. A final explicit ‘deny all’ is a security best practice. Starting with ‘application any’ would defeat the purpose of AppID and hurt performance.

In an active/active cluster, both nodes can forward traffic. Asymmetric routing occurs when the ingress flow for a session enters one node and the return flow enters the other. To handle this, the nodes must synchronize session state (created by the first packet). This is done by configuring ‘data-plane redundancy’ and ‘session-synchronization’ within redundancy groups. GRES is for chassis redundancy within a single node, the fab interface is for internal communication, and ISSU is for upgrades.

IDP policies have a fundamental operating mode: Detect or Prevent. ‘Detect’ mode will only log and generate alerts for matched signatures. ‘Prevent’ mode is required to actively drop, close, or otherwise mitigate the attack. Even if the rule action within the policy is ‘Drop and Log’, if the overall IDP policy is attached to a security policy in ‘Detect’ mode, no dropping will occur. The firewall policy permit action is required for the traffic to reach the IDP engine in the first place.

The most secure and explicit method is to create a custom application for the specific encrypted traffic (HTTPS) you wish to allow, and pair it with a deny policy for the unencrypted equivalent (HTTP). This uses the positive enforcement model (default deny) and provides clear intent. Relying on IPS or AppSecure for the core blocking intent is less direct and can be error-prone, while using ‘application any’ or a combined service set violates the requirement to explicitly block other web traffic.0