引用 | 編輯
anstd
2005-08-29 09:52 |
樓主
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11111111.11111111.11111111.00000000^^^^^^^^^^^^^^^^^^^ ----------------Rang範圍 0~255 Network Address Host Address 表示在同一段Network內,有0~255的Host Address 11111111.11111111.11111111.10000000 ^^^^^^^^^^^^^^^^^^^^^ ---------------Rang範圍0~127 Network Address Host Address 表示在同一段Network內,有0~127的Host Address 11111111.11111111.11111111.11100000 ^^^^^^^^^^^^^^^^^^^^^^ ---------------Rang範圍0~31 Network Address Host Address 表示在同一段Network內,有0~31的Host Address ((Netmask要點)) 1.網路位置(Network Address)必為連續的1 00000000 (2) 0 (10) 10000000 128 11000000 192 11100000 224 11110000 240 11111000 248 11111100 252 11111110 254 11111111 255 2.CIDR值 (看網路位置有多少個連續的1) 255.255.255.0 ==> CIDR=24 255.255.255.252 ==> CIDR=30 192.168.2.100/255.255.255.0 與 192.168.2.100/24 是相同的 CIDR=20 =>255.255.240.0 CIDR=25 =>255.255.255.128 若IP/Netmask 192.168.2.100/24 求IP Range IP Range = 192.168.2.0 ~ 192.168.2.255 若IP/Netmask 192.168.2.100/25 求IP Range IP Range = 192.168.2.0 ~ 192.168.2.127 Netmask: 255.255.255.0 => host:256 255.255.255.128 => host:128 255.255.255.192 => host:64 255.255.255.224 => host:32 255.255.255.240 => host:16 IP Range 第一個IP位置稱為網路位置(Network) 最後一個IP位置稱為廣撥位置(Broadcast) Network及Broadcast位置不可拿來使用 ex: 168.32.1.9/25 可用IP = 128-2=126 172.60.2.90/29 可用IP = 8-2=6 實例 ((HUB連接A與B)) netmask=255.255.255.0 A B IP 192.168.2.100 192.168.2.200 Netmask 255.255.255.0 255.255.255.0 Network 192.168.2.0 192.168.2.0 IP: 192.168.2.100(10) = 11000000.10101000.00000010.01100100(2) Netmask: 255.255.255.0(10) = 11111111.11111111.11111111.00000000(2) ----------------------------------------------------------------------------------------- Network: 192.168.2.0(10) = 11000000.10101000.00000010.00000000(2) ((AND運算法)) IP 192(10) 11000000(2) Netmask AND 255(10) 11111111(2) --------------------------------------------------- Network 192(10) 11000000(2) ((HUB連接A與B)) netmask=255.255.255.128 A B IP 192.168.2.100 192.168.2.200 Netmask 255.255.255.128 255.255.255.128 Network 192.168.2.0 192.168.2.128 <==將無法直接連線 IP: 192.168.2.100(10) = 11000000.10101000.00000010.01100100(2) Netmask: 255.255.255.128(10) = 11111111.11111111.11111111.10000000(2) ----------------------------------------------------------------------------------------- Network: 192.168.2.0(10) = 11000000.10101000.00000010.00000000(2) IP: 192.168.2.200(10) = 11000000.10101000.00000010.11001000(2) Netmask: 255.255.255.128(10) = 11111111.11111111.11111111.10000000(2) ----------------------------------------------------------------------------------------- Network: 192.168.2.128(10) = 11000000.10101000.00000010.10000000(2) 以上若有錯誤 還請大大指正..... x0
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