TECHNICAL ENGINEER EXAMINATION (NETWORK)(AFTERNOON, PART 1) doc

2001 Autumn Technical Engineer Examination (Network)(Afternoon Part 1) Questions must be answered in accordance with the following: Question Nos Q1 to Q4 Question Selection Select three of the above four Examination Time 12:30-14:00 (90 minutes) Instructions: Use an HB pencil If you need to change an answer, erase your previous answer completely and neatly Wipe away any eraser debris Mark your answers in accordance with the instructions below (1)Examinee Number Write your examinee number in the space provided, and mark the appropriate space below each digit (2)Date of Birth Write your date of birth (in numbers) exactly as it is printed on your examination admission card, and mark the appropriate space below each digit (3)Answers In the Selection column, circle the numbers of the questions that you are choosing to Any question that is not circled will not be scored If you circle all four questions, only the first three will be scored (4) Write each answer in the space specified for that question (5) Write your answers clearly and neatly Answer that is difficult to read will receive a lower score Do not open the exam booklet until instructed to so Inquiries about the exam questions will not be answered [List of Question Contents] Question No Theme Q1 Construction of a SOHO environment Q2 Expanding an application system that uses mobile communication equipment Q3 Electronic mail system operation Q4 Designing a network focusing on route design Questions [Description] Sub-Question (1) Basic knowledge regarding ISDN users and network interfaces Sub-Question (1) Basic knowledge regarding DHCP servers (2) Correctly sequencing sentences that describe the operations of a DHCP server and client (3) Method for detecting duplicate IP addresses Sub-Question Operational requirements for implementing DHCP server functions using a SOHO router [Illustration] Sub-Question (2) Completing an ISDN connection configuration [Calculation] Sub-Question ISDN communication charges [Description] Sub-Question (1) Basic knowledge regarding communication interfaces (2) Hardware used to establish a TCP connection Sub-Question (1) Effect on existing network (2) Details regarding changing the address of a Web server and its relocation (3) Bottleneck when using PDAs, effect on users, and measures to prevent this [Calculation] Sub-Question (1) Communication charges per query when using mobile telephones (2) Communication charges per query when using PDAs (3) Number of queries beyond which communication charges for a mobile telephone become cheaper than using a PDA [Description] Sub-Question Basic knowledge for implementing services for communications with customers Sub-Question Details regarding changing settings for automated response mail Sub-Question (1) Router functions required for security (2) Services required for routes that directly connect to an ISP (3) Services required for router connections Sub-Question (1) Problems which are not resolved even if an outsourcing proposal is implemented (2) Reason why checking for viruses continues for the in-house mail server (3) Reason why problems are resolved by dividing the firewall into two devices [Description] Sub-Question (1) Basic knowledge regarding user authentication procedures (2) Function that allows connections from outside even when the authentication server fails Sub-Question (1) Basic knowledge regarding routing (2) Changes in the routing table when a router fails Sub-Question (1) The hardware and settings needed to make a connection to Web server (2) Changes of the PC settings needed to allow a search of product information Sub-Question Location of the bottleneck when a router fails Q1 Read the following question regarding the construction of a SOHO environment and answer sub-questions through Mr A runs a real estate company and has an office near a train station A PC was installed in his office several years ago It is used for managing pieces of real estate and customers Now it was decided to change the system to a client-server model, and Mr A started to consult with Company B, with which he has had a close relationship for a long while After meeting many times regarding the system, Mr A made an additional request He wanted to have the system connected to the Internet so that he can contact landlords and obtain industry information Mr C is in charge of Company B and immediately proposed the system configuration shown in Fig Application server SOHO router ISDN ISP … Client Office Client Fig System Configuration Proposed by Company B The following is a conversation between Mr A and Mr C Mr C: I have been working on your request for the system to be connected to the Internet, and I have come up with the system configuration shown in Fig Mr A: Let’s check it over I can use the Internet even if the application server stops? Mr C: Yes, that’s not a problem Let me explain this configuration The hub of the configuration I proposed previously is replaced by a SOHO router that has both hub functions and ISDN connection functions This SOHO router will be connected to the ISDN line currently used with your fax machine Mr A: How much is this going to cost? Mr C: The cost per month is approximately as follows The connection to the ISP is $20 per month and the basic charge for the ISDN line does not change Since the access point to the ISP is in the city, the communication charge during connections is ¢8 per minutes So if you view web pages 30 minutes per day, and assuming that there are 25 work days per a month, it will cost $ Similarly, the cost of reading e-mails will be if you read them eight times per b day, two minutes each time, 25 days per month Mr A: Is a TA required to connect the ISDN line to the SOHO router? Mr C: No, it’s not necessary A TA is a terminal adaptor I’ll explain its role using this figure R TE2 S TA T NT2 U NT1 ISDN Fig Reference Configuration for ISDN Users with Network Interface Mr C: Fig shows the reference configuration for ISDN users with network interface as defined c by a standards organization NT1 in this figure is specifically called a TE2 refers to something other than a terminal which has been designed for use as a d The device required to connect NT2 and NT1 to this type of terminal is a TA Point R e point between the TA and TE2 refers to the f Although the router is a piece of hardware used to connect a different , as shown in the figure, a TA is not required if you are equipped with an ISDN interface such as that of the SOHO router which will be installed Table SOHO Router Interface Specifications (Excerpt) Interface Description Standard ITU-T G.961 Connector 6-pin modular jack Number of ports Standard ISDN interface (Point S/T) 8-pin modular jack Standard ISDN interface (Point U) Connector Number of ports LAN interface IEEE802.3 ITU-T I.430 Connector 8-pin modular jack Number of ports Mr A: I think I understand, but I still don’t understand completely Can you explain what kind of configuration the system will have if this SOHO router is used? Mr C: That’s shown in Fig TE1 is a piece of hardware that supports ISDN It is equivalent to a fax machine TE1 (fax) Omitted because this is the answer to a sub-question U NT1 ( ) ISDN Fig Connection Configuration Drawn by Mr C Mr A: Okay, I get it Now I finally understand the meaning of “point S/T” in that SOHO router catalog Mr C: The SOHO router has many various functions, and we will be using the DHCP server function in your system Mr A: What is DHCP? Mr C: We could use a special protocol if your system were just an application system We will use TCP/IP so that you can use the Internet Hardware connected to the LAN will be assigned IP addresses and addresses must be set for the DNS and gateway Use of DHCP makes these settings and hardware management easy Although it is also possible to use the application server as a DHCP server, the SOHO router will be used as the DHCP server out of consideration of operating conditions and requirements It may take a little while, but I will describe DHCP to you The following is a summary of Mr C’s description DHCP is an expansion of the protocol used so that clients can automatically g read network-related settings from a server It contains the added capability of dynamically assigning address information and other configuration information IP addresses are assigned as follows: Note that lines Ư through  below are out of order because sequencing them in the right order is to be asked by a sub-question ¦ The client sets the server ID and IP address and sends a DHCPREQUEST to the server The client broadcasts DHCPDISCOVER in order to find the server The value of the h destination MAC address in this frame is i and ¡ The server returns DHCPACK when the pooled IP addresses are returns DHCPNAK in all other cases ¢ The server returns DHCPOFFER Finally, the client checks consistency, and if there are no problems, finishes configuring the system The consistency check includes checking for duplicate IP addresses by using an ARP request The IP address is released by sending DHCPRELEASE to the server if the client has j finished using it before of the IP address Mr A: Okay, I understand Thank you for explaining it so well to the novice I will let you the system construction Mr C: Thank you Sub-Question Fill in the appropriate answers for boxes a Sub-Question Answer the following questions regarding ISDN c (1) Fill in the appropriate answers for boxes and b through in the text f in the text (2) Complete Fig used by Mr C Be sure to insert the correct hardware name in the parentheses and indicate Point S and Point T Sub-Question Answer the following questions regarding the DHCP server g (1) Fill in the appropriate answers for boxes through j in the text (2) Re-arrange lines Ư through Â, used to describe the operation between the server and the client, in the correct order (3) Explain in 80 words or less how duplicate IP addresses are detected Be sure to use the keywords “ARP request”, “the client’s own IP address”, and “client” Sub-Question Explain in 60 words or less which operating requirements caused Company B to propose that the DHCP server function be assigned to the SOHO router rather than to the application server Q2 Read the following description regarding expansion of a sales information system that uses mobile communication hardware, and answer sub-questions through Company E manages sales information using an application server and a Web server This sales system provides information regarding products, delivery dates and customers to sales personnel When used inside the office, the application server is accessed from client software running on a PC Some sales personnel also use the system from outside the office by accessing a Web server using HTTP from a browser running on a notebook PC When accessed this way, the Web server creates screens by dynamically using HTML while communicating with the application server In addition, some information which is not updated frequently (hereafter referred to as “local data”) is already downloaded to the PC inside the office so that it can be accessed from places the salesman visits Currently, Company E is studying the possibility of expanding this sales system Instead of notebook PCs, which take time to prepare for access, the new system will use new mobile communication devices The possible candidates for filling this role are a mobile telephone with a data display function (hereafter referred to as “mobile telephone”) or a PDA (Personal Digital Assistant) In addition, it is planned to enable all sales personnel to use the sales system from outside the office The following figure shows the network configuration of the sales information system In-house LAN LAN Application server Web Web server Internet Firewall GW GW server 11 Mobile telephone network Mobile telephone DMZ PDA GW GW server 22 RAS PHS network PHS Notebook PC PC PC Company E RAS RAS: Remote access server GW GW server: Gateway server Note: Parts of the system inside dotted lines are still being investigated Fig Network Configuration of the Sales Information System The in-house LAN has a private address and is connected to the Internet using a leased line through a firewall which uses IP filtering The system is also connected to the PHS network through a RAS which is located in the DMZ The RAS has as many ports as there are sales employees who will use the system Since new mobile communication equipment uses screen data having a unique format, a GW server is required to convert HTML screen data into screen data in this format The amount of data communicated between the GW server and the new mobile communication equipment is reduced to 50% of the current amount of data communicated using HTML and HTTP In the proposal which uses mobile telephones GW Server at the communication service provider will be used If PDAs are used, GW Server will be installed inside the office Since mobile telephones cannot store data, the use of local data becomes a problem On the other hand, local data can be stored in the built-in memory of a PDA In addition, PDAs have the external interface outlined in Table Table External Interface of a PDA Model Built-in External Interface name IrDA (specifications for SIR, IrLAP, IrLMP, etc defined by IrDA) TIA/EIA-232-E PIAFS (PHS Internet Access Forum Standard) ITU-T V.34 [Communication Costs] Company E produced a prototype of the query screen to be used by the new mobile communication equipment using HTML and accessed the prototype screen on the Web server from a notebook PC Results are given in Table When communication costs were calculated using this data, it was assumed that communication time lengths would be the same as given in Table regardless of the mobile communication equipment used The communication cost of network service is shown in Table Table Communication Time Lengths and Amount of Data Required for a Single Query Item Amount of time or data Communication time (the time from when a PHS network call was established until it was disconnected) 90 seconds Amount of data uploaded (from the notebook PC to the Web server) 1,280 bytes Amount of data downloaded (from the Web server to the notebook PC) 6,400 bytes Table Communication Costs of Network Service Item Mobile telephone network Communication charges (variable cost) ¢ Basic charges (fixed cost) PHS network /128 bytes ¢1/60 minutes $37/month $27/month [Proposal Comparison] The following is a conversation between Mr F and Mr G Mr F is the network engineer responsible for studying the network configuration and Mr G is his superior Mr G: I wonder if local data can be used by mobile telephones and PDAs Mr F: Since mobile telephones cannot store local data, when it is required it will be necessary to access the data on the application server from outside the company Mr G: Is it the same when using PDAs? Mr F: No Local data can be stored in PDA memory Local data does not all change every day If PDAs are used, data loaded on a salesman’s notebook PC can be transferred to the PDA The amount of data transferred can be reduced through a combination of data compression a and Based on trial calculations, the amount of data transferred per operation is 1/100 of the total amount of local data Mr G: PDAs have many interfaces Can you explain them to me? Mr F: IrDA is a data communication standard which uses originally intended as an interface between DTE and b c TIA/EIA-232-E is If we use PDAs, we will use IrDA inside the office Outside the office, we will use either PIAFS, which is a communication standard especially for the PHS network, or ITU-T V.34, which is a e d standard Of the two, half of sales personnel use the interface card for digital communications on their notebook PCs In the proposed plan to use PDAs, it seems we will be able to continue using this interface card, so we expect that the same mechanisms as available with the notebook PCs will be used for connecting to RAS and caller authentication Mr G: In the future, all sales personnel will use this system I'm concerned about the cost Mr F: I have calculated the cost per query If the system is to be used heavily, it is cheaper to use mobile telephones Mr G: Tell me about the effect on the existing network f Mr F: In both the proposals, it is necessary to change the settings of In the proposal to g use , it is necessary to change the IP address of the web server and to move it at the same time In another proposal, these changes not need to be made 10 Mr G: Is there anything else? Mr F: It is predicted that in future the number of access will be several times the current number The processing capabilities of the application server, Web server, and firewall will be sufficient However, if mobile telephones are used, access lines to the Internet will become a bottleneck Depending on the rate of use, there may be problems with the response time when accessing data from outside the office If this happens, it will be necessary to increase the speed of the access lines to the Internet In the proposal to uses PDAs, [The rest of Mr F’s response is omitted.] Mr G: I understand your explanation Let's work on the specific details of expanding the system after describing the plan to sales personnel Sub-Question Answer the following questions regarding the communication interface e a through (1) Fill in the appropriate answers for boxes in the text (2) Although the Web server communicates with the mobile communication equipment using TCP/IP, what hardware is used to establish the TCP connection at this time? Insert the proper hardware names into the figure for both the cases where notebook PCs are used and where PDAs are used Sub-Question Answer the following sub-questions regarding the communication costs required to make a query based on the description given in the text (1) What is the communication cost per query when using a mobile telephone? (2) What is the communication cost per query when using a PDA? (3) Comparing only the communication costs shown in Table 3, at least how many queries would a single salesman have to make from outside the company in one month, in order to make the communication cost of a mobile telephone cheaper than the communication cost of a PDA? Sub-Question Answer the following sub-questions regarding the effect on the existing network g f and (1) Fill in the appropriate answers for boxes g , what should be done to change the address and (2) In the proposal to use move the Web server? Explain in 150 words or less and include specific reasons (3) Explain in 100 words or less the bottleneck that occurs as the access count goes up when using PDAs, the effect on users, and what can be done about the problem 11 Q3 Read the following description regarding the administration of an e-mail system and answer sub-questions through Company S is a game software development company with 70 employees As shown in Fig 1, a Web server and e-mail (hereafter referred to as “mail”) server are installed in the company to customer service and to support in-house development This system is called an application system Mr U is in charge of the development and administration of this application system ISP Router Firewall DMZ Mail server for Web server Web outside mail In-house mail server Database server PC … DNS DNS server PC Fig Configuration of the Application System [Services of the Application System] The following can be said about services provided by the application system and those who benefit from it (1) Customers who purchase game software benefit from the system because Company S has established a homepage on a Web server with which they provide information such as announcing new products and giving dates when new games go on sale (2) Employees benefit from the system because it provides both an in-house mail system and method of sending/receiving mail to/from people outside the company This function is essential for developers, who make up a majority of total employees, so that they can communicate with companies cooperating in development and with sales companies (3) Developers benefit from the system because it allows them to view Web pages outside the company and use Internet games This function is essential for surveying new products from other companies (4) The customer service department benefits from the system because it is used as a method of contact with customers when providing services Details will be explained later (5) Other company employees benefit from the system because a virus check is performed by each mail server 12 [Service Related to Communications with Customers] Company S’s home page includes a page which allows customers to request reference materials To receive materials, a customer uses this page to register his or her home address and mail address The registered addresses and other information are stored by the database server After registration, workers in the Customer Service Department operate a a PC to convert information such as addresses into format, encrypt it using b , and send it to Company S’s distribution center The distribution center prints a destination address label and sends the material to the customer through the post office Recently, Mr U has changed the system to automatically send “thank you” e-mail when a customer requesting material has entered an e-mail address If there is a response to this “thank you” mail, it is assumed that the customer may have same opinions, and an automated response (automated response mail) is sent referring the customer to an opinion page on the Web site where they can enter their opinions During the development of “thank you” mail feature of the system, Mr U referred to c published by the IETF (Internet Engineering Task Force) Contents of the message followed standard specifications regarding mail headers, and a program for d sending commands to the mail server according to the mail transfer protocol was created and moved onto the Web server [Recent Problems] Mr U is currently dealing with the following problems ¦ Every year the importance of having customers view Company S’s home pages is growing Recently, the annual power source facility inspection has become a problem because it requires power supply in the building to be shut off for half a day If possible, Mr U would like the system to continue operation without shutting down About once per month the firewall is shut down for several hours to change firewall settings This is done to register IP addresses and port numbers so that developers can use the Internet games of other companies Since developers are notified beforehand that there is a planned shutdown of the firewall, the temporary halt in server is not a big problem to them, but Mr U does not want to halt services provided to customers ¡ A lot of work is required to change the settings mentioned in Problem above, and Mr U would like to reduce it ¢ Recently, the Security Committee established inside Company S has taken issue with increasing the available port numbers because it “increases the possibility of an attack from outside the company on customer information stored in the database.” The amount of work required to investigate whether port numbers can be made available has therefore increased greatly 13 £ “Thank you” mail sometimes enters an infinite loop creating complaints from customers ⁄ The Security Committee wants a survey based on log analysis to find out whether or not attacks from outside the company are taking place Although power outages due to external causes such as thunderstorms are rare, Mr U does not want services provided to customers to halt even by such rare occurrences [Countermeasures against Complaints from Customers] In the case of Problem £, it was found that the problem occurred when customers were using an automatic reply function such as used to indicate they are on vacation The reason is that the same address is set in the “REPLY-TO” field of the “Thank you” mail as set in the “REPLY-TO” field of the automated response mail and that the automated response mail is sent unconditionally in response to all mail having that destination address Mr U implemented a method of preventing this and solved the problem [Outsourcing Proposal] To resolve most of the other problems, a decision was made to study an outsourcing proposal This was implemented at a later date In this proposal, the firewall was divided into two parts, the firewall through which customers use the in-house Web pages and the firewall through which employees view the Web pages of companies, and some of the hardware was to be outsourced Fig shows this configuration and the part of the system that was outsourced Operations were outsourced to Company T, which operates an Internet Data Center Company T provides manned monitoring services and duplexed power facilities for operations 24 hours per day, 365 days per year ISP Company T ‚ ŽÐ Mail server for ŽÐŠ mail outside — ƒ ƒ‹ƒ ƒ DMZ ISP Company S ‚ ŽÐ Router ƒ‹ ƒ FW1 Web Web server ƒ ƒ Router ƒ‹ ƒ FW2 Router ƒ‹ ƒ Leased line Fig Outsourcing Proposal 14 DNS DNS server ƒ ƒ Router ƒ‹ ƒ In-house mail server Database server DMZ PC ƒ ƒ ƒ … ƒ ƒ PC ƒ The following optional services can also be used (1) Firewall management Version upgrade services and changes to hardware settings are performed according to a defined security policy (2) Intrusion detection service If any data is illegally sent or received, or if data is written onto the system except for performing maintenance, it is detected as an operation related to illegal access and log analysis is also performed (3) Virus protection service If mail is infected with a virus, the distribution of corresponding mail is halted Sub-Question a Select the appropriate answer from the items listed below list to insert in boxes d in the text regarding services related to communications with through customers a) CSV b) DES c) DSN d) ICMP e) POP f) RFC g) SMTP h) SNMP Sub-Question Explain in 80 words or less how the automated response mail settings were changed in the section [Preventing Complaints from Customers] Sub-Question Answer the following questions regarding the system configuration described in the section [Outsourcing Proposal] (1) Although Company S and Company T are connected by a router, required router functions include security-related functions, not just routing functions Explain this function in 25 words or less (2) For which service is the route that directly connects Company S to the ISP is required? Select one from the items listed (1) through (5) in the section [Services of the Application System] (4) For which service is the router connection between Company S and Company T is required for which service? Select three from the items listed (1) through (5) in the section [Services of the Application System] Sub-Question Answer the following sub-questions regarding problems solved by the [Outsourcing] (1) Which problems were not solved by implementing the outsourcing proposal? Answer based on items numbered ¦ through in the section [Recent Problems] (2) As a result of investigations by Mr U, the in-house mail server will continue checking for viruses even though virus protection service will be used Explain the reason for this in 50 words or less (3) Explain in 100 words or less why Problem ¢ was resolved by dividing the firewall into two parts 15 Q4 Read the following description regarding network design which focuses on route design and answer sub-questions through Company X sells electronic devices and has a main office in Tokyo and a branch office in Osaka, with five sales offices in the Kanto region, and five in the Kansai Products handled by Company X come in various models and with various functions, and the product cycle for these products is short Company X runs a product information server that can be used with HTTP in order to assist sales activities by providing product information in a timely manner Currently, Company X has an in-house TCP/IP-based network that has been configured by connecting a LAN at the main office to LANs at the branch office and each of the sales offices using ISDN lines with a communication speed of 64,000 bps As a result of the recent growth in the use of PCs by its employees, there is a strong demand from the branch office and sales offices for improved response time when using the server installed in the main office and when using the Internet via the LAN at the main office In addition, there is also a strong demand among employees who want to use the product information server even from outside the office In light of this situation, a decision has been made to re-construct the in-house network Due to this decision, Mr Y, the manager of the Information Systems Department has instructed Mr Z to design a new network Quickly beginning his investigation into possible new network designs, Mr Z has created Figure and described it to Mr Y as follows: Mr Y: Will this configuration improve response times? Mr Z: In light of enhancing the information system and increasing use of the Internet, the guaranteed communication speed will be made two times as fast as the current speed In addition, by installing a server in Osaka, it will be possible to distribute traffic and the load on the server Specifically, sales offices in the Kanto area (Kanto sales offices) will use the server in the main office, while sales offices in the Kansai area (Kansai sales offices) will use the server at the branch office in Osaka To this, the databases at the main office and branch office will replicate each other In addition, to keep traffic on the FR network down, an HTTP and FTP proxy server will be installed at each of the sales offices I think this will offer sufficient improvement Mr Y: Will these changes greatly increase communication costs? 16 Mr Z: In the FR service, a leased line (hereafter referred to as an “access line”) charge and a logical path usage charge will be required up to the access point However, it is expected that communication costs will go down because the logical path usage charge is a fixed charge independent of distance or the amount of communication Internet Main office R0 DMZ Product AuthentiApplicainformation cation tion server server server Osaka branch office Public server Firewall Authentication server Product information Application server server 192.168.20.0 192.168.30.0 R20 1.5 Mbps R21 R31 128 kbps 128 kbps R30 1.5 Mbps CIR1 CIR1 CIR1 CIR1 CIR2 192 kbps Sales office 1 Proxy server … RAS 192 kbps 192 kbps Sales office Proxy server Proxy server R5 R6 192.168.5.0 PC 192.168.6.0 RAS RAS Kanto sales offices Sales office 10 10 192.168.10.0 PC PHS network PHS Notebook PC … NotebookPC PCs PCs e1 s1 R1 Note: “e1” and “s1” indicate the router interface for Router R1 CIR1 128 kbps CIR2 64 kbps A communication speed of 128 kbps is guaranteed for CIR1 and a communication speed of 64 kbps is guaranteed for CIR2 Fig Configuration of the New Network 17 Proxy server R10 … Kansai sales offices Rn: Router Rn bps: bits per second bps RAS: Remote Access Server RAS FR FR: Frame Relay CIR2 Sales office 5 192.168.1.0 PC CIR2 192 kbps s1 R1 e1 CIR2 FR network FR CIR1 RAS PC Mr Y: I understand How are connections made from outside the company? Mr Z: With RAS hardware installed in each sales office, employees can connect from outside the office to the LAN at their office via a PHS network to which notebook PC’s are connected Mr Y: How is user authentication going to be handled? Mr Z: Authentication will be performed using a combination of CHAP and RADIUS Mr Z then used Figures and to describe the user authentication system to Mr Y Notebook PC b a (1) Call established (2) LCP session established (3) c (4) User ID and d (5) e (4) User ID and f (6) Result of authentication (7) PPP session established (When authenticated) LCP : Link Control Protocol PPP : Point to Point Protocol Fig User authentication Procedure Mr Y: How much thought have you given to preventing system failures? Mr Z: Two logical paths, CIR1 and CIR2, will be established between each sales office and the main office and the branch office With this configuration, communications will usually be performed using CIR1 However, if there is a problem with the router or access line at the main office or the branch office, the router’s dynamic routing will switch the logical path to CIR2 In addition, if a problem occurs with the product information server itself, it is possible to switch the server by changing PC and notebook PC settings Mr Y: If that happens, is it necessary to change router settings as well? Mr Z: With this design it is possible to continue using PCs without changing router settings Mr Y: That puts me at easy Let’s go forward with your proposal, Mr Z 18 Sub-Question Answer the following sub-questions regarding the user authentication procedure shown in Fig iv i through (1) Fill in the appropriate answers for boxes (2) Explain in 50 words or less the type of function that is required to change PC settings to allow searching of product information so that employees in the Kanto sales offices can connect from outside the office even if a problem occurs with the authentication server at the main office Sub-Question Answer the following sub-questions regarding routing control for the new network shown in Fig i iii (1) Fill in the appropriate symbols or figures for boxes through found in Table Table Part of the Routing Table for R1 NO Interface DLCI Network address Number of hops s1 16 192.168.20.0 s1 17 192.168.30.0 i s1 16 192.168.10.0 ii e1 - iii Note: DLCI: Data Link Connection Identifier (2) If a problem occurs with R20, the line indicated as NO.1 in Table changes as shown and in Table Fill in the appropriate figures for boxes ¦ Table Part of the Routing Table for R1 if R20 Fails NO Interface DLCI Network address s1 ¦ Hop number of hops 192.168.20.0 Sub-Question Answer the following sub-questions regarding hardware settings (1) From the sales office 10 shown in Fig 1, what kind of settings are required for which hardware in order to make connections to the Web server on the Internet via R20? Explain in 50 words or less and be sure to include the names of the hardware and the specific settings required (2) Explain in 100 words or less the changes to PC settings necessary to allow a search of product information from a PC in a Kanto sales office if problems occur with the product information server at the main office Sub-Question If R30 fails, which part of the network shown in Fig is likely to become a bottleneck? Explain in 30 words or less For this question, assume that there is sufficient router capability and that PC settings are not changed 19 ... focusing on route design Questions [Description] Sub-Question (1) Basic knowledge regarding ISDN users and network interfaces Sub-Question (1) Basic knowledge regarding DHCP servers (2) Correctly sequencing... communication charges [Description] Sub-Question (1) Basic knowledge regarding communication interfaces (2) Hardware used to establish a TCP connection Sub-Question (1) Effect on existing network (2) Details... Sub-Question (1) Router functions required for security (2) Services required for routes that directly connect to an ISP (3) Services required for router connections Sub-Question (1) Problems which