Free Juniper JN0-232 Practice Exam with Questions & Answers | Set: 2

Security policies on SRX support several actions:

Permit:Allows traffic to pass according to the rule.

Deny:Silently drops the traffic without notifying the source.

Reject:Drops the trafficand sends a TCP RST (for TCP) or ICMP unreachable (for UDP/other protocols)back to the source. This provides feedback to the sending host.

Next-policy:Allows policy chaining to evaluate the next policy set.

Therefore, the action that causes traffic to drop and a message to be sent to the source isreject.

From the exhibit:

The user attempted to access https://www.wikipedia.org.

The block page indicates:

CATEGORY: NG_Reference

REASON: BY_PRE_DEFINED

The header states:“Juniper Web Filtering has been set to block this site.”

Analysis of options:

Option A:Correct. The log shows “REASON: BY_PRE_DEFINED,” which means the site was blocked because it matched apredefined categoryin the Web filtering database.

Option B:Correct. The category “NG_Reference” indicates that theNextGen (Enhanced/Cloud-based) Web Filtering typeis being used.

Option C:Incorrect. The exhibit does not provide any information about SSL proxy configuration; it only shows that the HTTPS site was blocked.

Option D:Incorrect. The block page shown is the standard Juniper default block page, not a custom message.

Correct Statements:The URL matches a predefined Web filtering category, and the NextGen Web Filtering type is being used.

Option B:Correct. Interfaces in the same security zone must belong to the same routing instance; zones cannot span multiple routing instances.

Option D:Correct. A security zone can contain multiple interfaces, allowing grouping of similar trust levels (e.g., multiple LAN subnets in a trust zone).

Option A:Incorrect. An interface can belong to only one zone at a time.

Option C:Incorrect. Interfaces within the same zone cannot be split across routing instances.

Correct Statements:Interfaces in the same zone must share the same routing instance, and a zone can contain multiple interfaces.

NextGen Web Filtering (NGWF) requires SSL proxy functionality to inspect HTTPS traffic. To enable NGWF:

Option B:You can generate aself-signed certificatefor SSL proxy functionality (or import a CA-signed certificate, but the course emphasizes self-signed for lab/demo purposes).

Option D:You must configure anSSL proxy profileso that HTTPS traffic can be decrypted and inspected.

Option A:A CA-signed certificate may be used in production but is not strictly required to enable NGWF.

Option C:SSL initiation profiles are used for outbound SSL inspection initiated by the SRX, not for NGWF traffic interception.

Correct Actions:Generate a self-signed certificate, Configure an SSL proxy profile

Unified security policies integratetraditional zone-based policieswithapplication-based policies. Their characteristics include:

Zone-based or global (Option B):Unified policies can be applied as either zone-specific or global policies.

AppID engine (Option C):They leverage the AppID engine for application identification, enabling fine-grained control at the application layer.

Policy matching (Option A):Policies are evaluated sequentially like standard security policies; applications are not matched before policy processing.

Multiple matches (Option D):If multiple policies could match, the first match applies (sequential order), not the “most restrictive.”

Correct Statements:B and C

When a packet enters an SRX interface, aroute lookupis performed:

It determines theegress interface(Option B) by checking the destination IP against the routing table.

Once the egress interface is known, its associatedegress security zone(Option D) is also determined.

Theingress interface (Option A)is already known when the packet arrives, so the route lookup does not determine it.

DNS name (Option C):DNS is unrelated to routing lookups.

Correct Results:egress interface, egress security zone

In Junos OS, NAT rules are evaluated intop-down order. When a new rule is added, it is placed at thebottomof the rule set by default.

To move a rule to the top of the rule set, the command is:

set security nat source rule-set rule top

Option A (top):Correct. Moves the specified rule to the top of the list.

Option B (run):Used to execute operational commands, not rule reordering.

Option C (up):Not valid for reordering NAT rules.

Option D (insert):Not a supported NAT reordering command in Junos.

Correct Command:top

Screen options are used to detect and prevent attacks such as floods, scans, and malformed packets. In some cases,false positivesmay occur, where legitimate traffic is mistakenly identified as malicious.

To address this, administrators can configure thealarm-without-dropoption (Option D). This setting generates alarms/logs for suspicious traffic without actually dropping it, allowing verification before taking further action.

Enabling all screen options (Option A) may increase false positives further.

Discarding traffic immediately (Option B) risks disrupting legitimate communication.

Increasing sensitivity (Option C) worsens the problem, since false positives would increase.

Correct Action:Use alarm-without-drop to log the traffic without dropping it.

Juniper SRX evaluatessecurity policies in order, top to bottom. The first matching policy determines the action, and no further policies are evaluated. This behavior can lead toshadowed policiesif later policies match the same conditions as earlier ones.

From the exhibit:

Policy1:Matches application junos-http and permits traffic.

Policy2:Matches application junos-https and permits traffic.

Policy3:Matches application junos-http again, but denies traffic.

Sincepolicy1already matches all HTTP traffic and permits it, traffic never reachespolicy3. This makespolicy3 shadowedbecause it has the same match condition as policy1 but is evaluated later in the list.

Other options:

Policy1 is not shadowed because it is evaluated first.

Policy2 is independent (application = HTTPS) and therefore unaffected.

Only policy3 is shadowed by policy1.

Correct Statement:Policy3 will be shadowed because it matches the same application as policy1.