CCNA Practice Questions-1
Q1 ) What is the Cisco Catalyst store-and-forward switching method ?
Ans In this mode switches receives the entire frame before it forwards it. The switch reads the cyclic redundancy check (CRC) to make sure the frame is not bad. If the frame is good, the switch forwards it. Because the switch stores the frame before forwarding it, latency is introduced in the switch. Latency through the switch varies with the size of the the frame.
Q2) Whatr are the three switching methods in Cisco Catalyst Switches ?
- Store-and-forward
- Cut-through
- Fragment-free
Q3) What is the Cisco Catalyst fragment free switching method ?
Ans In fragement free switching , it checks the first 64 bytes of the frame. Ethernet specifications state that collision should be detected during the first 64 bytes of the frame. By reading the first 64 bytes of the frame the swtich can filter most collisions, although late collisions are still possible.
Q4) What is the Cisco Catalyst cut-through-switching method?
Ans In cut through switching mode, the switch only checks the frame’s destination addresss and immediately begin forwarding the frame out the appropriate port. Because the switch only checks the destination address in only the header and nothe the entire frame, the switch forwards a collision frame or a frame that has a bad CRC.
Q5) What is half-duplex transmission mode ?
Ans Half-duplex transmission is the default mode that Ethernet functions in. In half-duplex transmission, a device can only send or receive-not do both at once. In half duplex mode, stations are susceptible to collisions, and efficiency is rated at 50 to 60percent.
Q6) What is full-duplex transmission mode ?
Ans) In full duplex mode a station can send and receive data at the same time. In full-duplex mode collision detection is disabled. This mode offers100percent efficiency in both directions.
Q7) What is the default switching mode in Cisco Catalyst 1900 switches ?
Ans The default switching mode for the Catalyst 1900 is fragment free.