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Addressing of Internet. Koji OKAMURA Kyushu University. Quiz. An university use 192.168.0.0/22 for whole campus network and there are three departments in the university; A,B,C. Department A uses 192.168.0.0/23 Department B uses 192.168.2.0/26
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Addressing of Internet Koji OKAMURA Kyushu University
Quiz • An university use 192.168.0.0/22 for whole campus network and there are three departments in the university; A,B,C. • Department A uses 192.168.0.0/23 • Department B uses 192.168.2.0/26 • Department C has about 250 PCs. Which network address should be assigned to Department C? Information Network
Addressing of Internet Protocol Router Router Router Information Network
Addressing of Internet Protocol #5 #1 Router 1 2 3 1 2 3 #3 Router #2 1 2 3 #6 Router #4 1 2 3 Internet Address = Network ID (#?) + Host ID (1~3) Network IP address is IP address of which all of host ID’s bit is 0. Broadcast address is IP address of which all of host ID’s bit is 1. Information Network
ClassA,B,C Class A 01000000101010000000101000100001 Class B 10000000101010000000101000100001 Class C 11000000101010000000101000100001 Information Network
ClassA Class A 01000000101010000000101000100001 • Network Address • 1.0.0.0 – 127.0.0.0 • Host Address • 1.0.0.1 – 1.255.255.254 Information Network
ClassB Class B 10000000101010000000101000100001 • Network Address • 128.0.0.0 – 191.255.0.0 • Host Address • 128.0.0.1 – 128.0.255.254 Information Network
ClassC Class C 11000000101010000000101000100001 • Network Address • 192.0.0.0 – 223.255.255.0 • Host Address • 192.0.0.1 – 192.0.0.254 Information Network
ClassD(Multicast) Class D 11100000101010000000101000100001 • Network Address • 224.0.0.0 – 239.255.255.255 Information Network
クラスレス(Classless Inter-Domain Routing:CIDR) Class C 11000000101010000000101000100001 Classless 11000000101010000000101000100001 192.168.10.33/22 Information Network
Address Assignment based on Class Class B 2^14 Class A 2^7 Class C 2^21
CIDR:Classless Inter-Domain Routing クラスB 2^14 クラスA 2^7 クラスC 2^21 Prefix = network address + length Many Prefixes 268,500
What’s the problem of many prefixes? ISP ISP University ISP ISP A border BGP router must imports full routing information from all of peering ISP. Information Network