Firewall Filters JN0-105 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network administrator is configuring a firewall filter to block Telnet traffic from the 192.168.10.0/24 subnet to a specific server at 10.0.0.5. The filter must allow all other traffic. The administrator creates a term named 'block-telnet' with the match condition 'source-address 192.168.10.0/24; destination-address 10.0.0.5/32; protocol tcp; destination-port 23;' and the action 'discard'. After applying this filter to the server's interface in the inbound direction, the administrator notices that Telnet traffic from the 192.168.10.0/24 subnet to the server is still working. What is the most likely reason for this behavior?

   • AThe filter term is missing the 'from' stanza, so the match conditions are not being evaluated.
   • BThe filter was applied in the outbound direction on the server's interface, so it is not inspecting inbound Telnet traffic.
   • CThe filter term is missing the 'then reject' action, so the traffic is being accepted by default.
   • DThe 'discard' action silently drops the packet, but the server is responding with a TCP RST, which the client interprets as a successful connection.
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2. 2foundation · easy

   What is the default action for a packet that does not match any term in a firewall filter?

   • Aaccept
   • Bdiscard
   • Cnext-term
   • Dreject
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4. 3foundation · easy

   You need to match HTTP traffic in a firewall filter. Which combination of match conditions is required?

   • Aprotocol icmp and destination-port 80
   • Bprotocol tcp and source-port 80
   • Cprotocol udp and destination-port 53
   • Dprotocol tcp and destination-port 80
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5. 4foundation · easy

   You suspect a firewall filter is not matching traffic as expected. What is a common first step to troubleshoot this issue?

   • AReboot the device to clear the filter state
   • BChange the filter action to 'accept' for all terms
   • CCheck the filter match counters using 'show firewall filter <name> statistics'
   • DDelete the filter and recreate it from scratch
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6. 5foundation · easy

   How does Junos evaluate terms within a firewall filter?

   • AAll terms are evaluated simultaneously and the most specific match wins
   • BIn random order based on the term name
   • CIn reverse order, from bottom to top
   • DIn the order they appear in the configuration, from top to bottom
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