I will aim at the chief telecommunications engineer's qualification acquisition.

Well, I think that have the problem of the network system seen after a long time today. The problem of such a network system and the protocol system increases in recent years, too and the person who has challenged a technical engineer might grapple easily with chief telecommunications engineer's problem up to now. Then, today's material is [kochira] ↓.



- Function of router etc.



The function to judge right or wrong of the street of the packet is provided for one thing in each port number of the protocol in the transport layer, and the access from the outside by a specific protocol of the FTP etc. can restrict no permission etc. of the filtering function of the router.

These sentences are correct.
- It is a description of "Access list".



In the static routing method that is one of the setting methods of the routing table of the router, information is automatically comparatively converted between routers at a long interval time day and generally every month, etc. and the routing table is renewed.

These sentences are wrong.
- In the dynamic routing method that is one of the methods of setting the routing table of the router, information is automatically comparatively exchanged between routers at a long interval time generally day or every month, etc. and the routing table is renewed.
- The update doesn't do the routing table to the static routing by the automatic operation.



In RIP2(RIP Vervion2) that is one of the routing protocols of the dynamic routing method, using it from no function of the transmission of subnet mask information on the network composed of a variable-length subnet is unsuitable.

These sentences are wrong.
- In RIP2, the field of message formats not used is used, and the field of the route tag, the subnet mask, and the next hop is increased. Moreover, the IP multicast became available because of the load reduction of the network, too. Therefore, the function to transmit subnet mask information exists.
- When it is RIPv1, subnet information be able to be done certainly and come to do RIPv2 though it is incommunicable.



Three layer switches that are composed of the hardware subject because the performance that the router possesses is becoming a bottleneck on the network and work at high speed are developed, and the high-speed packet forwarding technologies of the store and the forward method, etc. are used.

These sentences are wrong.
- These sentences are explanations of cutting the through method. There is a merit that the priority control and error correction can be done instead of lacking at high speed (real time) because the transmission delay is generated unlike the circuit switching method when the store and the forward method (stored and forward switching system) are introduced.
- Neither the store nor the forward are so early. (Accumulate the packet and priority control and because it is done that the error is corrected. )

- As such, a free fragmentation is early (Because only the header part is confirmed).
- Cut and the through is the earliest (Because the packet is forwarded without confirming it).



Well, how?Sleeping then around here today though it is thought that it was a comparatively gentle problem if it is not good at problem of such a genre ..might take the study of a technical engineer and CCNA/CCIP for a moment by you..