Free Cisco 640-821 Exam Dumps Questions & Answers

A network administrator cannot get a router serial interface to become active. The administrator suspects that the problem may be the cable attached to the interface. The administrator is not at the same physical location as the router. Which Cisco IOS command allows the administrator to check the serial 0/0 cabling type?

• A.  show version
• B.  show interfaces serial 0/0
• C.  show running-config
• D.  show controllers serial 0/0
• E.  show startup-config

How many simultaneous Telnet sessions does a Cisco router support by default?

• A.  3
• B.  2
• C.  1
• D.  5
• E.  4
• F.  6

A receiving host has failed to receive all of the segments that it should acknowledge. What can the host do to improve the reliability of this communication session?

• A.  decrease the window size
• B.  use a different source port for the session
• C.  obtain a new IP address from the DHCP server
• D.  decrease the sequence number
• E.  start a new session using UDP

Why is the show processes command used on a router before a debug command is entered?

• A.  to verify the IOS version that is running
• B.  to check if the load meter file has enough space left to store the output of the debug command
• C.  to verify the amount of space in flash memory
• D.  to verify that the CPU utilization is low enough to handle the effects of a debug command
• E.  to view the number of timers that are currently in use

What command will disable CDP on a router interface?

• A.  router(config-if)# no cdp active
• B.  router(config-if)# no cdp
• C.  router(config-if)# no cdp run
• D.  router(config-if)# no cdp enable