Book excerpt: Our 1500+ Computer Networks questions and answers focuses on all areas of Computer Networks subject covering 100+ topics in Operating Systems. These topics are chosen from a collection of most authoritative and best reference books on Computer Networks. One should spend 1 hour daily for 15 days to learn and assimilate Computer Networks comprehensively. This way of systematic learning will prepare anyone easily towards Computer Networks interviews, online tests, examinations and certifications. Highlights Ø 1500+ Basic and Hard Core High level Multiple Choice Questions & Answers in Computer Networks with explanations. Ø Prepare anyone easily towards Computer Networks interviews, online tests, Government Examinations and certifications. Ø Every MCQ set focuses on a specific topic in Computer Networks. Ø Specially designed for IBPS IT, SBI IT, RRB IT, GATE CSE, UGC NET CS, PROGRAMMER and other IT & Computer Science related exams. Who should Practice these Operating Systems Questions? Ø Anyone wishing to sharpen their skills on Computer Networks. Ø Anyone preparing for aptitude test in Computer Networks. Ø Anyone preparing for interviews (campus/off-campus interviews, walk-in interview and company interviews) Ø Anyone preparing for entrance examinations and other competitive examinations. Ø All – Experienced, Freshers and Students. Computer Networks Basics --------------------------------------------------------------------6 Access Networks --------------------------------------------------------------------------------10 Reference Models ------------------------------------------------------------------------------13 Physical Layer ------------------------------------------------------------------------------------17 Data Link Layer -----------------------------------------------------------------------------------19 Network Layer ------------------------------------------------------------------------------------21 Transport Layer ----------------------------------------------------------------------------------23 Topology -------------------------------------------------------------------------------------------25 Multiplexing --------------------------------------------------------------------------------------27 Delays and Loss ----------------------------------------------------------------------------------29 Network Attacks ---------------------------------------------------------------------------------31 Physical Media -----------------------------------------------------------------------------------33 Packet Switching & Circuit Switching -------------------------------------------------------35 Application Layer - ------------------------------------------------------------------------------37 HTTP ------------------------------------------------------------------------------------------------41 HTTP & FTP ---------------------------------------------------------------------------------------44 FTP --------------------------------------------------------------------------------------------------46 SMTP -----------------------------------------------------------------------------------------------48 DNS--------------------------------------------------------------------------------------------------52 SSH --------------------------------------------------------------------------------------------------54 DHCP -----------------------------------------------------------------------------------------------56 IPSecurity -----------------------------------------------------------------------------------------58 Virtual Private Networks ----------------------------------------------------------------------60 SMI -------------------------------------------------------------------------------------------------63 SNMP -----------------------------------------------------------------------------------------------66 TELNET ---------------------------------------------------------------------------------------------69 TCP --------------------------------------------------------------------------------------------------72 UDP -------------------------------------------------------------------------------------------------77 AH and ESP Protocols --------------------------------------------------------------------------80 Congestion Control -----------------------------------------------------------------------------83 Virtual Circuit -------------------------------------------------------------------------------------86 ATM & Frame Relay -----------------------------------------------------------------------------89 WWW ----------------------------------------------------------------------------------------------93 IPv4 & Addressing -------------------------------------------------------------------------------95 IPv6 & Addressing -------------------------------------------------------------------------------99 P2P Applications --------------------------------------------------------------------------------103 ICMP -----------------------------------------------------------------------------------------------106 Transition from IPV4 to IPV6 ----------------------------------------------------------------109 IPV4 and IPV6 Comparision ------------------------------------------------------------------111 Analyzing Subnet Masks ----------------------------------------------------------------------114 Designing Subnet Masks ----------------------------------------------------------------------117 IP Routing -----------------------------------------------------------------------------------------121 RIP v1 ----------------------------------------------------------------------------------------------125 RIP v2 ----------------------------------------------------------------------------------------------128 Cryptography ------------------------------------------------------------------------------------131 PORTS ---------------------------------------------------------------------------------------------134 Socket Programming --------------------------------------------------------------------------137 Cookies --------------------------------------------------------------------------------------------139 Web Caching -------------------------------------------------------------------------------------142 Packet Forwarding & Routing ---------------------------------------------------------------145 Security in The Internet -----------------------------------------------------------------------147 OSPF -----------------------------------------------------------------------------------------------149 OSPF Configuration ----------------------------------------------------------------------------152 Datagram Networks ---------------------------------------------------------------------------156 Firewalls ------------------------------------------------------------------------------------------159 Network Management ------------------------------------------------------------------------162 Network Utilities -------------------------------------------------------------------------------165 ETHERNET ----------------------------------------------------------------------------------------167 WIRELESS LAN ----------------------------------------------------------------------------------169 INTERNET ----------------------------------------------------------------------------------------171 BLUETOOTH -------------------------------------------------------------------------------------173 WiMax --------------------------------------------------------------------------------------------175 SONET ---------------------------------------------------------------------------------------------177 RTP -------------------------------------------------------------------------------------------------179 RPC ------------------------------------------------------------------------------------------------181 Intrusion Detection Systems ----------------------------------------------------------------183 PPP -------------------------------------------------------------------------------------------------186 EIGRP ----------------------------------------------------------------------------------------------189 STP -------------------------------------------------------------------------------------------------191 600 MCQ TEST YOURSELF- RANDOM EXERCISE -----------------------------------194-284