Multiple choice

Refer to the exhibit. An administrator has configured two access lists on R1. The list inbound on the serial interface is named Serial and the list inbound on the LAN interface is named LAN. What affect will be produced by the access control lists?

  1. PC1 will be able to telnet to PC3.

  2. R3 will not be able to communicate with PC1 and PC3.

  3. PC3 cannot telnet to R3 and cannot communicate with PC1.

  4. PC1 will not be able to telnet to R3 and PC3 will not be able to communicate with PC1.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The two ACLs (Serial inbound and LAN inbound) are blocking specific traffic flows. From the correct answer, the Serial ACL is blocking PC1's telnet traffic to R3, while the LAN ACL is blocking PC3's communication with PC1. ACLs are processed in order and applied to traffic in the specified direction (inbound means entering the interface). Without seeing the exact ACL rules and network exhibit, the administrator must have configured rules that deny these specific flows while permitting others. Telnet uses TCP port 23, which the Serial ACL apparently blocks for PC1-to-R3 traffic.

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