{"id":24,"date":"2025-07-16T13:44:55","date_gmt":"2025-07-16T04:44:55","guid":{"rendered":"https:\/\/34.64.61.65\/?p=24"},"modified":"2025-07-16T14:26:21","modified_gmt":"2025-07-16T05:26:21","slug":"tcp_ip%ec%99%80_%eb%84%a4%ed%8a%b8%ec%9b%8c%ed%81%ac_%ed%94%84%eb%a1%9c%ed%86%a0%ec%bd%9c_%ec%89%bd%ea%b2%8c_%ec%9d%b4%ed%95%b4%ed%95%98%ea%b8%b0","status":"publish","type":"post","link":"https:\/\/hed-g.me\/?p=24","title":{"rendered":"TCP\/IP\uc640 \ub124\ud2b8\uc6cc\ud06c \ud504\ub85c\ud1a0\ucf5c \uc27d\uac8c \uc774\ud574\ud558\uae30: \uac1c\ubc1c\uc790\ub97c \uc704\ud55c \ub124\ud2b8\uc6cc\ud06c \uae30\ucd08 \uc644\uc804\uc815\ubcf5"},"content":{"rendered":"\n

\uc548\ub155\ud558\uc138\uc694, \uc131\uc7a5\ud558\ub294 \uac1c\ubc1c\uc790 \uc5ec\ub7ec\ubd84!<\/p>\n\n\n\n

“\ub124\ud2b8\uc6cc\ud06c\ub294 \uc5b4\ub835\ub2e4”, “\uc65c \uc778\ud130\ub137\uc774 \uc548 \ub420\uae4c?”\ub77c\uace0 \uc0dd\uac01\ud574\ubcf8 \uc801 \uc788\uc73c\uc2e0\uac00\uc694? \uc6f9 \uc560\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \ub9cc\ub4e4\uba74\uc11c\ub3c4 HTTP \uc694\uccad\uc774 \uc2e4\uc81c\ub85c \uc5b4\ub5bb\uac8c \uc804\ub2ec\ub418\ub294\uc9c0, \uc65c \uac00\ub054 timeout\uc774 \ubc1c\uc0dd\ud558\ub294\uc9c0 \uad81\uae08\ud588\uc744 \uac81\ub2c8\ub2e4.<\/p>\n\n\n\n

\uc624\ub298\uc740 \uac1c\ubc1c\uc790\ub85c\uc11c \uaf2d \uc54c\uc544\uc57c \ud560 TCP\/IP\uc640 \ub124\ud2b8\uc6cc\ud06c \ud504\ub85c\ud1a0\ucf5c<\/strong>\uc5d0 \ub300\ud574 \uc27d\uace0 \uc7ac\ubbf8\uc788\uac8c \uc54c\uc544\ubcf4\uaca0\uc2b5\ub2c8\ub2e4. \ubcf5\uc7a1\ud55c \uc774\ub860\ubcf4\ub2e4\ub294 \uc2e4\ubb34\uc5d0\uc11c \ubc14\ub85c \uc368\uba39\uc744 \uc218 \uc788\ub294 \uc9c0\uc2dd \uc704\uc8fc\ub85c \uc124\uba85\ub4dc\ub9b4\uac8c\uc694!<\/p>\n\n\n\n

1. \ub124\ud2b8\uc6cc\ud06c\uc758 \uae30\ubcf8: \uc65c \ud504\ub85c\ud1a0\ucf5c\uc774 \ud544\uc694\ud560\uae4c?<\/h2>\n\n\n\n

\ud504\ub85c\ud1a0\ucf5c\uc774\ub780?<\/h3>\n\n\n\n

\ud504\ub85c\ud1a0\ucf5c\uc740 \ucef4\ud4e8\ud130\ub07c\ub9ac \ub300\ud654\ud558\ub294 \uc57d\uc18d<\/strong>\uc785\ub2c8\ub2e4. \ub9c8\uce58 \ud55c\uad6d\uc5b4\ub97c \ubaa8\ub974\ub294 \uc678\uad6d\uc778\uacfc \ub300\ud654\ud558\ub824\uba74 \uc601\uc5b4\ub77c\ub294 \uacf5\ud1b5 \uc5b8\uc5b4\uac00 \ud544\uc694\ud55c \uac83\ucc98\ub7fc, \ucef4\ud4e8\ud130\ub4e4\ub3c4 \uc11c\ub85c \ud1b5\uc2e0\ud558\uae30 \uc704\ud55c \uacf5\ud1b5 \uc5b8\uc5b4\uac00 \ud544\uc694\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n

\uc0ac\ub78c \uac04 \ub300\ud654: \ud55c\uad6d\uc5b4, \uc601\uc5b4, \uc911\uad6d\uc5b4...\n\ucef4\ud4e8\ud130 \uac04 \ub300\ud654: TCP\/IP, HTTP, FTP...<\/code><\/pre>\n\n\n\n
\ud328\ud0b7 \ud1b5\uc2e0\uc758 \uc6d0\ub9ac<\/h3>\n\n\n\n
\ud070 \ub370\uc774\ud130\ub97c \ud55c \ubc88\uc5d0 \ubcf4\ub0b4\uc9c0 \uc54a\uace0 \uc791\uc740 \uc870\uac01(\ud328\ud0b7)<\/strong>\uc73c\ub85c \ub098\ub204\uc5b4 \ubcf4\ub0c5\ub2c8\ub2e4. \ub9c8\uce58 \uae34 \ud3b8\uc9c0\ub97c \uc5ec\ub7ec \uc7a5\uc758 \uc5fd\uc11c\ub85c \ub098\ub204\uc5b4 \ubcf4\ub0b4\ub294 \uac83\uacfc \uac19\uc8e0.<\/p>\n\n\n\n
\uc6d0\ubcf8 \ub370\uc774\ud130: \"\uc548\ub155\ud558\uc138\uc694 \ubc18\uac11\uc2b5\ub2c8\ub2e4\"\n\ud328\ud0b7 1: \"\uc548\ub155\" + [1\/3\ubc88\uc9f8 \uc870\uac01]\n\ud328\ud0b7 2: \"\ud558\uc138\uc694\" + [2\/3\ubc88\uc9f8 \uc870\uac01]\n\ud328\ud0b7 3: \"\ubc18\uac11\uc2b5\ub2c8\ub2e4\" + [3\/3\ubc88\uc9f8 \uc870\uac01]<\/code><\/pre>\n\n\n\n
\uac01 \ud328\ud0b7\uc5d0\ub294 \ud5e4\ub354<\/strong>\ub77c\ub294 \uc8fc\uc18c\ub85d\uc774 \ubd99\uc5b4\uc788\uc5b4\uc11c, \ubaa9\uc801\uc9c0\uc5d0\uc11c \uc6d0\ub798 \uc21c\uc11c\ub300\ub85c \uc870\ub9bd\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n
2. OSI 7\uacc4\uce35: \ub124\ud2b8\uc6cc\ud06c\uc758 \uacc4\uce35 \uad6c\uc870<\/h2>\n\n\n\n
\uc65c \uacc4\uce35\uc73c\ub85c \ub098\ub20c\uae4c?<\/h3>\n\n\n\n
\ubcf5\uc7a1\ud55c \ub124\ud2b8\uc6cc\ud06c \ud1b5\uc2e0\uc744 \ub2e8\uacc4\ubcc4\ub85c \ub098\ub204\uc5b4 \uac01\uac01\uc758 \uc5ed\ud560\uc744 \uba85\ud655\ud788 \ud558\uae30 \uc704\ud574\uc11c\uc785\ub2c8\ub2e4. \ub9c8\uce58 \ud0dd\ubc30 \ubc30\uc1a1 \uc2dc\uc2a4\ud15c\ucc98\ub7fc \uac01 \ub2e8\uacc4\ub9c8\ub2e4 \ub2f4\ub2f9\uc790\uac00 \uc788\ub294 \uac83\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n
7. \uc751\uc6a9 \uacc4\uce35 (Application)    - \ube0c\ub77c\uc6b0\uc800, \uc774\uba54\uc77c \uc571\n6. \ud45c\ud604 \uacc4\uce35 (Presentation)  - \ub370\uc774\ud130 \uc554\ud638\ud654, \uc555\ucd95\n5. \uc138\uc158 \uacc4\uce35 (Session)       - \uc5f0\uacb0 \uad00\ub9ac\n4. \uc804\uc1a1 \uacc4\uce35 (Transport)     - TCP, UDP\n3. \ub124\ud2b8\uc6cc\ud06c \uacc4\uce35 (Network)    - IP, \ub77c\uc6b0\ud305\n2. \ub370\uc774\ud130\ub9c1\ud06c \uacc4\uce35 (Data Link) - \uc774\ub354\ub137, WiFi\n1. \ubb3c\ub9ac \uacc4\uce35 (Physical)      - \ucf00\uc774\ube14, \uc804\ud30c<\/code><\/pre>\n\n\n\n
\uc2e4\ubb34\uc5d0\uc11c \uc911\uc694\ud55c \uacc4\uce35\ub4e4<\/h3>\n\n\n\n
4\uacc4\uce35 (\uc804\uc1a1 \uacc4\uce35) – TCP\/UDP<\/strong><\/p>\n\n\n\n
# TCP \uc5f0\uacb0 \ud655\uc778\nnetstat -an | grep ESTABLISHED\n\n# \ud2b9\uc815 \ud3ec\ud2b8 \ub9ac\uc2a4\ub2dd \ud655\uc778\nnetstat -tulpn | grep :80<\/code><\/pre>\n\n\n\n
3\uacc4\uce35 (\ub124\ud2b8\uc6cc\ud06c \uacc4\uce35) – IP<\/strong><\/p>\n\n\n\n
# \ub77c\uc6b0\ud305 \ud14c\uc774\ube14 \ud655\uc778\nroute -n\nip route show\n\n# \ub124\ud2b8\uc6cc\ud06c \uacbd\ub85c \ucd94\uc801\ntraceroute google.com<\/code><\/pre>\n\n\n\n
3. IP \uc8fc\uc18c: \uc778\ud130\ub137\uc758 \uc8fc\uc18c \uccb4\uacc4<\/h2>\n\n\n\n
IP \uc8fc\uc18c\uc758 \uad6c\uc870<\/h3>\n\n\n\n
IP \uc8fc\uc18c\ub294 32\ube44\ud2b8\uc758 \uc774\uc9c4\uc218<\/strong>\uc774\uc9c0\ub9cc, \uc0ac\ub78c\uc774 \uc77d\uae30 \uc27d\uac8c 4\uac1c\uc758 \uc2ed\uc9c4\uc218<\/strong>\ub85c \ud45c\ud604\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n
\uc774\uc9c4\uc218: 11000000.10101000.00000001.00000001\n\uc2ed\uc9c4\uc218: 192.168.1.1<\/code><\/pre>\n\n\n\n
IP \uc8fc\uc18c \ud074\ub798\uc2a4<\/h3>\n\n\n\n
Class A (\ub300\uaddc\ubaa8 \ub124\ud2b8\uc6cc\ud06c)<\/strong><\/p>\n\n\n\n
    \n
  • \ubc94\uc704: 1.0.0.0 ~ 126.255.255.255<\/li>\n\n\n\n
  • \ub124\ud2b8\uc6cc\ud06c\ubd80: \uccab \ubc88\uc9f8 \uc625\ud15f<\/li>\n\n\n\n
  • \ud638\uc2a4\ud2b8\ubd80: \ub098\uba38\uc9c0 3\uc625\ud15f<\/li>\n\n\n\n
  • \uc608: \ub300\ud559\uad50, \ub300\uae30\uc5c5<\/li>\n<\/ul>\n\n\n\n
    Class B (\uc911\uac04 \uaddc\ubaa8 \ub124\ud2b8\uc6cc\ud06c)<\/strong><\/p>\n\n\n\n
      \n
    • \ubc94\uc704: 128.0.0.0 ~ 191.255.255.255<\/li>\n\n\n\n
    • \ub124\ud2b8\uc6cc\ud06c\ubd80: \uccab \ubc88\uc9f8, \ub450 \ubc88\uc9f8 \uc625\ud15f<\/li>\n\n\n\n
    • \ud638\uc2a4\ud2b8\ubd80: \ub098\uba38\uc9c0 2\uc625\ud15f<\/li>\n<\/ul>\n\n\n\n
      Class C (\uc18c\uaddc\ubaa8 \ub124\ud2b8\uc6cc\ud06c)<\/strong><\/p>\n\n\n\n
        \n
      • \ubc94\uc704: 192.0.0.0 ~ 223.255.255.255<\/li>\n\n\n\n
      • \ub124\ud2b8\uc6cc\ud06c\ubd80: \uccab \ubc88\uc9f8~\uc138 \ubc88\uc9f8 \uc625\ud15f<\/li>\n\n\n\n
      • \ud638\uc2a4\ud2b8\ubd80: \ub9c8\uc9c0\ub9c9 \uc625\ud15f<\/li>\n\n\n\n
      • \uc608: \uc77c\ubc18 \uac00\uc815, \uc18c\uaddc\ubaa8 \uc0ac\ubb34\uc2e4<\/li>\n<\/ul>\n\n\n\n
        \uc0ac\uc124 IP vs \uacf5\uc778 IP<\/h3>\n\n\n\n
        \uc0ac\uc124 IP (Private IP)<\/strong><\/p>\n\n\n\n
        Class A: 10.0.0.0 ~ 10.255.255.255\nClass B: 172.16.0.0 ~ 172.31.255.255\nClass C: 192.168.0.0 ~ 192.168.255.255<\/code><\/pre>\n\n\n\n
        NAT(Network Address Translation)<\/strong><\/p>\n\n\n\n
          \n
        • \uc0ac\uc124 IP\ub97c \uacf5\uc778 IP\ub85c \ubcc0\ud658<\/li>\n\n\n\n
        • IP \uc8fc\uc18c \ubd80\uc871 \ubb38\uc81c \ud574\uacb0<\/li>\n\n\n\n
        • \ubcf4\uc548 \ud6a8\uacfc<\/li>\n<\/ul>\n\n\n\n
          # \ub0b4\ubd80 IP \ud655\uc778\nip addr show\nifconfig\n\n# \uc678\ubd80 IP \ud655\uc778\ncurl ifconfig.me<\/code><\/pre>\n\n\n\n
          \uc11c\ube0c\ub137 \ub9c8\uc2a4\ud06c<\/h3>\n\n\n\n
          \ub124\ud2b8\uc6cc\ud06c\ubd80\uc640 \ud638\uc2a4\ud2b8\ubd80\ub97c \uad6c\ubd84\ud558\ub294 \uc5ed\ud560\uc744 \ud569\ub2c8\ub2e4.<\/p>\n\n\n\n
          IP: 192.168.1.100\n\uc11c\ube0c\ub137 \ub9c8\uc2a4\ud06c: 255.255.255.0 (\/24)\n\n\ub124\ud2b8\uc6cc\ud06c \uc8fc\uc18c: 192.168.1.0\n\ube0c\ub85c\ub4dc\uce90\uc2a4\ud2b8 \uc8fc\uc18c: 192.168.1.255\n\uc0ac\uc6a9 \uac00\ub2a5\ud55c \ud638\uc2a4\ud2b8: 192.168.1.1 ~ 192.168.1.254<\/code><\/pre>\n\n\n\n
          4. TCP vs UDP: \uc2e0\ub8b0\uc131 vs \uc18d\ub3c4<\/h2>\n\n\n\n
          TCP (Transmission Control Protocol)<\/h3>\n\n\n\n
          \ud2b9\uc9d5<\/strong><\/p>\n\n\n\n
            \n
          • \uc5f0\uacb0 \uc9c0\ud5a5\uc801<\/strong>: 3-way handshake\ub85c \uc5f0\uacb0 \ud655\ub9bd<\/li>\n\n\n\n
          • \uc2e0\ub8b0\uc131 \ubcf4\uc7a5<\/strong>: \ub370\uc774\ud130 \uc190\uc2e4 \uc2dc \uc7ac\uc804\uc1a1<\/li>\n\n\n\n
          • \uc21c\uc11c \ubcf4\uc7a5<\/strong>: \ud328\ud0b7\uc774 \uc21c\uc11c\ub300\ub85c \ub3c4\ucc29<\/li>\n\n\n\n
          • \uc18d\ub3c4 \uc0c1\ub300\uc801\uc73c\ub85c \ub290\ub9bc<\/strong><\/li>\n<\/ul>\n\n\n\n
            3-way Handshake<\/strong><\/p>\n\n\n\n
            \ud074\ub77c\uc774\uc5b8\ud2b8 \u2192 \uc11c\ubc84: SYN (\uc5f0\uacb0 \uc694\uccad)\n\uc11c\ubc84 \u2192 \ud074\ub77c\uc774\uc5b8\ud2b8: SYN+ACK (\uc694\uccad \uc218\ub77d)\n\ud074\ub77c\uc774\uc5b8\ud2b8 \u2192 \uc11c\ubc84: ACK (\uc5f0\uacb0 \ud655\ub9bd)<\/code><\/pre>\n\n\n\n
            \uc0ac\uc6a9 \uc608\uc2dc<\/strong><\/p>\n\n\n\n
              \n
            • HTTP\/HTTPS (\uc6f9)<\/li>\n\n\n\n
            • FTP (\ud30c\uc77c \uc804\uc1a1)<\/li>\n\n\n\n
            • SMTP (\uc774\uba54\uc77c)<\/li>\n\n\n\n
            • SSH (\uc6d0\uaca9 \uc811\uc18d)<\/li>\n<\/ul>\n\n\n\n
              UDP (User Datagram Protocol)<\/h3>\n\n\n\n
              \ud2b9\uc9d5<\/strong><\/p>\n\n\n\n
                \n
              • \ube44\uc5f0\uacb0\uc131<\/strong>: \uc0ac\uc804 \uc5f0\uacb0 \uacfc\uc815 \uc5c6\uc74c<\/li>\n\n\n\n
              • \uc2e0\ub8b0\uc131 \ubbf8\ubcf4\uc7a5<\/strong>: \ub370\uc774\ud130 \uc190\uc2e4 \uac00\ub2a5<\/li>\n\n\n\n
              • \uc21c\uc11c \ubbf8\ubcf4\uc7a5<\/strong>: \ud328\ud0b7 \uc21c\uc11c\uac00 \ubc14\ub014 \uc218 \uc788\uc74c<\/li>\n\n\n\n
              • \uc18d\ub3c4 \ube60\ub984<\/strong><\/li>\n<\/ul>\n\n\n\n
                \uc0ac\uc6a9 \uc608\uc2dc<\/strong><\/p>\n\n\n\n
                  \n
                • DNS (\ub3c4\uba54\uc778 \uc870\ud68c)<\/li>\n\n\n\n
                • DHCP (IP \uc790\ub3d9 \ud560\ub2f9)<\/li>\n\n\n\n
                • \uc2e4\uc2dc\uac04 \uc2a4\ud2b8\ub9ac\ubc0d<\/li>\n\n\n\n
                • \uc628\ub77c\uc778 \uac8c\uc784<\/li>\n<\/ul>\n\n\n\n
                  # TCP \ud3ec\ud2b8 80 \ud655\uc778\ntelnet google.com 80\n\n# UDP DNS \ucffc\ub9ac\nnslookup google.com<\/code><\/pre>\n\n\n\n
                  5. \ub124\ud2b8\uc6cc\ud06c \uc7a5\ube44: \ub370\uc774\ud130\uc758 \uc5ec\ud589<\/h2>\n\n\n\n
                  NIC (Network Interface Card)<\/h3>\n\n\n\n
                  \ucef4\ud4e8\ud130\ub97c \ub124\ud2b8\uc6cc\ud06c\uc5d0 \uc5f0\uacb0\ud558\ub294 \uad00\ubb38<\/strong> \uc5ed\ud560\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n
                  # \ub124\ud2b8\uc6cc\ud06c \uc778\ud130\ud398\uc774\uc2a4 \uc815\ubcf4 \ud655\uc778\nip link show\nethtool eth0  # \uc774\ub354\ub137 \uc815\ubcf4<\/code><\/pre>\n\n\n\n
                  \ud5c8\ube0c (Hub)<\/h3>\n\n\n\n
                    \n
                  • \ub9ac\ud53c\ud130 \uc5ed\ud560<\/strong>: \uc2e0\ud638\ub97c \uadf8\ub300\ub85c \uc99d\ud3ed\ud558\uc5ec \uc7ac\uc804\uc1a1<\/li>\n\n\n\n
                  • \ucf5c\ub9ac\uc804 \ub3c4\uba54\uc778<\/strong>: \uc5f0\uacb0\ub41c \ubaa8\ub4e0 \uc7a5\ube44\uac00 \ud558\ub098\uc758 \ucda9\ub3cc \uc601\uc5ed<\/li>\n\n\n\n
                  • \ub2e8\uc810<\/strong>: \ub300\uc5ed\ud3ed \uacf5\uc720, \ubcf4\uc548 \ucde8\uc57d<\/li>\n\n\n\n
                  • \ud604\uc7ac<\/strong>: \uac70\uc758 \uc0ac\uc6a9\ud558\uc9c0 \uc54a\uc74c (\uc2a4\uc704\uce58\ub85c \ub300\uccb4)<\/li>\n<\/ul>\n\n\n\n
                    \uc2a4\uc704\uce58 (Switch)<\/h3>\n\n\n\n
                    \ud5c8\ube0c\uc640\uc758 \ucc28\uc774\uc810<\/strong><\/p>\n\n\n\n
                      \n
                    • MAC \uc8fc\uc18c \ud559\uc2b5<\/strong>: \uc5b4\ub5a4 \ud3ec\ud2b8\uc5d0 \uc5b4\ub5a4 \uc7a5\ube44\uac00 \uc5f0\uacb0\ub418\uc5b4 \uc788\ub294\uc9c0 \uae30\uc5b5<\/li>\n\n\n\n
                    • \ucf5c\ub9ac\uc804 \ub3c4\uba54\uc778 \ubd84\ub9ac<\/strong>: \uac01 \ud3ec\ud2b8\uac00 \ub3c5\ub9bd\uc801\uc778 \ucda9\ub3cc \uc601\uc5ed<\/li>\n\n\n\n
                    • \uc804\uc774\uc911 \ud1b5\uc2e0<\/strong>: \ub3d9\uc2dc\uc5d0 \uc1a1\uc2e0\uacfc \uc218\uc2e0 \uac00\ub2a5<\/li>\n<\/ul>\n\n\n\n
                      \uc2a4\uc704\uce58\uc758 \ub3d9\uc791 \uacfc\uc815<\/strong><\/p>\n\n\n\n
                        \n
                      1. Learning<\/strong>: MAC \uc8fc\uc18c\ub97c \ubc30\uc6b0\uace0 \ud14c\uc774\ube14\uc5d0 \uc800\uc7a5<\/li>\n\n\n\n
                      2. Flooding<\/strong>: \ubaa8\ub974\ub294 \uc8fc\uc18c\uba74 \ubaa8\ub4e0 \ud3ec\ud2b8\ub85c \uc804\uc1a1<\/li>\n\n\n\n
                      3. Forwarding<\/strong>: \uc544\ub294 \uc8fc\uc18c\uba74 \ud574\ub2f9 \ud3ec\ud2b8\ub85c\ub9cc \uc804\uc1a1<\/li>\n\n\n\n
                      4. Filtering<\/strong>: \uac19\uc740 \uc138\uadf8\uba3c\ud2b8 \ub0b4 \ud1b5\uc2e0\uc740 \ucc28\ub2e8<\/li>\n<\/ol>\n\n\n\n
                        # MAC \uc8fc\uc18c \ud14c\uc774\ube14 \ud655\uc778 (\uc2a4\uc704\uce58\uc5d0\uc11c)\nshow mac address-table\n\n# ARP \ud14c\uc774\ube14 \ud655\uc778 (PC\uc5d0\uc11c)\narp -a\nip neigh show<\/code><\/pre>\n\n\n\n
                        \ub77c\uc6b0\ud130 (Router)<\/h3>\n\n\n\n
                        \uc5ed\ud560<\/strong><\/p>\n\n\n\n
                          \n
                        • \ube0c\ub85c\ub4dc\uce90\uc2a4\ud2b8 \ub3c4\uba54\uc778 \ubd84\ub9ac<\/strong>: \ub124\ud2b8\uc6cc\ud06c\ub97c \ub17c\ub9ac\uc801\uc73c\ub85c \ubd84\ud560<\/li>\n\n\n\n
                        • \uacbd\ub85c \uacb0\uc815<\/strong>: \ucd5c\uc801\uc758 \uacbd\ub85c\ub85c \ud328\ud0b7 \uc804\uc1a1<\/li>\n\n\n\n
                        • \ubcf4\uc548<\/strong>: \ud328\ud0b7 \ud544\ud130\ub9c1, \ubc29\ud654\ubcbd \uae30\ub2a5<\/li>\n<\/ul>\n\n\n\n
                          \uae30\ubcf8 \uac8c\uc774\ud2b8\uc6e8\uc774 (Default Gateway)<\/strong><\/p>\n\n\n\n
                          # \uae30\ubcf8 \uac8c\uc774\ud2b8\uc6e8\uc774 \ud655\uc778\nroute -n | grep 0.0.0.0\nip route | grep default\n\n# \uac8c\uc774\ud2b8\uc6e8\uc774 \uc5f0\uacb0 \ud14c\uc2a4\ud2b8\nping 192.168.1.1<\/code><\/pre>\n\n\n\n
                          6. \uc2e4\ubb34 \ub124\ud2b8\uc6cc\ud06c \uc9c4\ub2e8 \ub3c4\uad6c<\/h2>\n\n\n\n
                          \uae30\ubcf8 \uc5f0\uacb0\uc131 \ud14c\uc2a4\ud2b8<\/h3>\n\n\n\n
                          # \uae30\ubcf8 ping \ud14c\uc2a4\ud2b8\nping google.com\n\n# \ud328\ud0b7 \uc190\uc2e4\ub960\uacfc RTT \ud655\uc778\nping -c 10 google.com\n\n# IPv6 ping\nping6 google.com<\/code><\/pre>\n\n\n\n
                          \uacbd\ub85c \ucd94\uc801<\/h3>\n\n\n\n
                          # \uacbd\ub85c \ucd94\uc801 (Linux\/Mac)\ntraceroute google.com\n\n# \uacbd\ub85c \ucd94\uc801 (Windows)\ntracert google.com\n\n# MTR (\uc9c0\uc18d\uc801\uc778 \uacbd\ub85c \ucd94\uc801)\nmtr google.com<\/code><\/pre>\n\n\n\n
                          \ud3ec\ud2b8 \uc5f0\uacb0 \ud14c\uc2a4\ud2b8<\/h3>\n\n\n\n
                          # \ud2b9\uc815 \ud3ec\ud2b8 \uc5f0\uacb0 \ud14c\uc2a4\ud2b8\ntelnet google.com 80\nnc -zv google.com 80\n\n# \uc5ec\ub7ec \ud3ec\ud2b8 \uc2a4\uce94\nnmap -p 22,80,443 google.com<\/code><\/pre>\n\n\n\n
                          DNS \uc870\ud68c<\/h3>\n\n\n\n
                          # \uae30\ubcf8 DNS \uc870\ud68c\nnslookup google.com\ndig google.com\n\n# \ud2b9\uc815 \ub808\ucf54\ub4dc \ud0c0\uc785 \uc870\ud68c\ndig google.com MX\ndig google.com AAAA<\/code><\/pre>\n\n\n\n
                          \ub124\ud2b8\uc6cc\ud06c \uc0c1\ud0dc \ubaa8\ub2c8\ud130\ub9c1<\/h3>\n\n\n\n
                          # \ud65c\uc131 \uc5f0\uacb0 \ud655\uc778\nnetstat -tuln\nss -tuln\n\n# \ub300\uc5ed\ud3ed \uc0ac\uc6a9\ub7c9 \ubaa8\ub2c8\ud130\ub9c1\niftop\nnethogs\n\n# \uc2e4\uc2dc\uac04 \ub124\ud2b8\uc6cc\ud06c \ud1b5\uacc4\nwatch -n 1 cat \/proc\/net\/dev<\/code><\/pre>\n\n\n\n
                          7. \uc2e4\ubb34 \ubb38\uc81c \ud574\uacb0 \uac00\uc774\ub4dc<\/h2>\n\n\n\n
                          \ubb38\uc81c 1: “\uc778\ud130\ub137\uc774 \uc548 \ub429\ub2c8\ub2e4”<\/h3>\n\n\n\n
                          \uc9c4\ub2e8 \uc21c\uc11c<\/strong><\/p>\n\n\n\n
                          # 1. \ub85c\uceec \uc778\ud130\ud398\uc774\uc2a4 \ud655\uc778\nip addr show\n\n# 2. \uac8c\uc774\ud2b8\uc6e8\uc774 \uc5f0\uacb0 \ud655\uc778\nping 192.168.1.1\n\n# 3. DNS \uc11c\ubc84 \ud655\uc778\nping 8.8.8.8\n\n# 4. \ub3c4\uba54\uc778 \ud574\uc11d \ud655\uc778\nnslookup google.com\n\n# 5. \uc678\ubd80 \uc5f0\uacb0 \ud655\uc778\nping google.com<\/code><\/pre>\n\n\n\n
                          \ubb38\uc81c 2: “\uc11c\ubc84\uc5d0 \uc5f0\uacb0\uc774 \uc548 \ub429\ub2c8\ub2e4”<\/h3>\n\n\n\n
                          # \ud3ec\ud2b8 \uc5f4\ub9bc \ud655\uc778\ntelnet server-ip 80\n\n# \ubc29\ud654\ubcbd \ud655\uc778\nsudo iptables -L\nsudo firewall-cmd --list-all\n\n# \uc11c\ube44\uc2a4 \uc0c1\ud0dc \ud655\uc778\nsudo systemctl status nginx\nsudo netstat -tulpn | grep :80<\/code><\/pre>\n\n\n\n
                          \ubb38\uc81c 3: “\ub124\ud2b8\uc6cc\ud06c\uac00 \ub290\ub9bd\ub2c8\ub2e4”<\/h3>\n\n\n\n
                          # \ub300\uc5ed\ud3ed \ud14c\uc2a4\ud2b8\nspeedtest-cli\n\n# \ub124\ud2b8\uc6cc\ud06c \uc9c0\uc5f0 \ud655\uc778\nping -c 100 google.com | tail -1\n\n# \uacbd\ub85c\uc0c1 \ubcd1\ubaa9 \uc9c0\uc810 \ud655\uc778\nmtr google.com<\/code><\/pre>\n\n\n\n
                          8. \uac1c\ubc1c\uc790\ub97c \uc704\ud55c \ub124\ud2b8\uc6cc\ud06c \ucd5c\uc801\ud654 \ud301<\/h2>\n\n\n\n
                          HTTP \uc131\ub2a5 \ucd5c\uc801\ud654<\/h3>\n\n\n\n
                          # Keep-Alive \uc5f0\uacb0 \ud655\uc778\ncurl -I -H \"Connection: keep-alive\" http:\/\/example.com\n\n# \uc555\ucd95 \ud655\uc778\ncurl -H \"Accept-Encoding: gzip\" -I http:\/\/example.com<\/code><\/pre>\n\n\n\n
                          DNS \ucd5c\uc801\ud654<\/h3>\n\n\n\n
                          # DNS \uce90\uc2dc \ud50c\ub7ec\uc2dc\nsudo systemctl flush-dns  # Linux\nsudo dscacheutil -flushcache  # Mac\n\n# \ube60\ub978 DNS \uc11c\ubc84 \uc0ac\uc6a9\necho \"nameserver 1.1.1.1\" | sudo tee \/etc\/resolv.conf<\/code><\/pre>\n\n\n\n
                          \ub85c\ub4dc\ubc38\ub7f0\uc2f1\uacfc CDN<\/h3>\n\n\n\n
                          \/\/ Node.js\uc5d0\uc11c \ud074\ub7ec\uc2a4\ud130\ub9c1\nconst cluster = require(\"cluster\");\nconst numCPUs = require(\"os\").cpus().length;\n\nif (cluster.isMaster) {\n  for (let i = 0; i < numCPUs; i++) {\n    cluster.fork();\n  }\n} else {\n  \/\/ \uc6cc\ucee4 \ud504\ub85c\uc138\uc2a4\n  require(\".\/app.js\");\n}<\/code><\/pre>\n\n\n\n
                          \ub9c8\uce58\uba70: \ub124\ud2b8\uc6cc\ud06c \ub9c8\uc2a4\ud130\ub85c\uc758 \uc5ec\uc815<\/h2>\n\n\n\n
                          \uc624\ub298 \ubc30\uc6b4 \ub0b4\uc6a9\uc744 \uc815\ub9ac\ud558\uba74:<\/p>\n\n\n\n
                            \n
                          1. \ud504\ub85c\ud1a0\ucf5c\uc740 \ucef4\ud4e8\ud130 \uac04\uc758 \uc57d\uc18d<\/strong><\/li>\n\n\n\n
                          2. TCP\ub294 \uc2e0\ub8b0\uc131, UDP\ub294 \uc18d\ub3c4<\/strong><\/li>\n\n\n\n
                          3. IP \uc8fc\uc18c\ub294 \uc778\ud130\ub137\uc758 \uc8fc\uc18c<\/strong><\/li>\n\n\n\n
                          4. \uc2a4\uc704\uce58\ub294 MAC \uc8fc\uc18c, \ub77c\uc6b0\ud130\ub294 IP \uc8fc\uc18c\ub85c \ub3d9\uc791<\/strong><\/li>\n\n\n\n
                          5. \ubb38\uc81c \ubc1c\uc0dd \uc2dc \uccb4\uacc4\uc801\uc778 \uc9c4\ub2e8\uc774 \uc911\uc694<\/strong><\/li>\n<\/ol>\n\n\n\n
                            \uc2e4\ubb34\uc5d0\uc11c \uae30\uc5b5\ud560 \uc810<\/h3>\n\n\n\n
                              \n
                            • \ub2e8\uacc4\ubcc4 \uc9c4\ub2e8<\/strong>: \ubb3c\ub9ac \uacc4\uce35\ubd80\ud130 \uc751\uc6a9 \uacc4\uce35\uae4c\uc9c0 \uc21c\ucc28\uc801\uc73c\ub85c<\/li>\n\n\n\n
                            • \ub85c\uadf8 \ud655\uc778<\/strong>: \ubaa8\ub4e0 \ubb38\uc81c\uc758 \ub2f5\uc740 \ub85c\uadf8\uc5d0 \uc788\ub2e4<\/li>\n\n\n\n
                            • \ubaa8\ub2c8\ud130\ub9c1<\/strong>: \ud3c9\uc0c1\uc2dc \ub124\ud2b8\uc6cc\ud06c \uc0c1\ud0dc\ub97c \ud30c\uc545\ud574\ub450\uc790<\/li>\n\n\n\n
                            • \ubc31\uc5c5 \uacbd\ub85c<\/strong>: \uc911\uc694\ud55c \uc11c\ube44\uc2a4\ub294 \uc774\uc911\ud654 \uad6c\uc131<\/li>\n<\/ul>\n\n\n\n
                              \ub124\ud2b8\uc6cc\ud06c\ub294 \ud55c \ubc88\uc5d0 \ub2e4 \uc774\ud574\ud558\uae30 \uc5b4\ub824\uc6b4 \ubd84\uc57c\uc785\ub2c8\ub2e4. \ud558\uc9c0\ub9cc \uc624\ub298 \ubc30\uc6b4 \uae30\ucd08\ub97c \ubc14\ud0d5\uc73c\ub85c \uc2e4\ubb34\uc5d0\uc11c \ud558\ub098\uc529 \uacbd\ud5d8\ud574 \ub098\uac00\ub2e4 \ubcf4\uba74, \uc5b4\ub290\uc0c8 \ub124\ud2b8\uc6cc\ud06c \uc804\ubb38\uac00\uac00 \ub418\uc5b4 \uc788\uc744 \uac70\uc608\uc694!<\/p>\n\n\n\n
                              \uae30\uc5b5\ud558\uc138\uc694<\/strong>: \ub124\ud2b8\uc6cc\ud06c \ubb38\uc81c\uc758 80%\ub294 \uae30\ubcf8\uae30\ub85c \ud574\uacb0\ub429\ub2c8\ub2e4. \ud83c\udf10<\/p>\n","protected":false},"excerpt":{"rendered":"
                              \uc548\ub155\ud558\uc138\uc694, \uc131\uc7a5\ud558\ub294 \uac1c\ubc1c\uc790 \uc5ec\ub7ec\ubd84! “\ub124\ud2b8\uc6cc\ud06c\ub294 \uc5b4\ub835\ub2e4”, “\uc65c \uc778\ud130\ub137\uc774 \uc548 \ub420\uae4c?”\ub77c\uace0 \uc0dd\uac01\ud574\ubcf8 \uc801 \uc788\uc73c\uc2e0\uac00\uc694? \uc6f9 \uc560\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \ub9cc\ub4e4\uba74\uc11c\ub3c4 HTTP \uc694\uccad\uc774 \uc2e4\uc81c\ub85c \uc5b4\ub5bb\uac8c \uc804\ub2ec\ub418\ub294\uc9c0, \uc65c \uac00\ub054 timeout\uc774 \ubc1c\uc0dd\ud558\ub294\uc9c0 \uad81\uae08\ud588\uc744 \uac81\ub2c8\ub2e4. \uc624\ub298\uc740 \uac1c\ubc1c\uc790\ub85c\uc11c \uaf2d \uc54c\uc544\uc57c \ud560 TCP\/IP\uc640 \ub124\ud2b8\uc6cc\ud06c \ud504\ub85c\ud1a0\ucf5c\uc5d0 \ub300\ud574 \uc27d\uace0 \uc7ac\ubbf8\uc788\uac8c \uc54c\uc544\ubcf4\uaca0\uc2b5\ub2c8\ub2e4. \ubcf5\uc7a1\ud55c \uc774\ub860\ubcf4\ub2e4\ub294 \uc2e4\ubb34\uc5d0\uc11c \ubc14\ub85c \uc368\uba39\uc744 \uc218 \uc788\ub294 \uc9c0\uc2dd \uc704\uc8fc\ub85c \uc124\uba85\ub4dc\ub9b4\uac8c\uc694! 1. \ub124\ud2b8\uc6cc\ud06c\uc758 \uae30\ubcf8: \uc65c \ud504\ub85c\ud1a0\ucf5c\uc774 \ud544\uc694\ud560\uae4c? […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[57],"tags":[65,63,59,64],"class_list":["post-24","post","type-post","status-publish","format-standard","hentry","category-network","tag-osi-7-layer","tag-tcp-ip","tag-59","tag-64"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/posts\/24","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hed-g.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=24"}],"version-history":[{"count":2,"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions"}],"predecessor-version":[{"id":62,"href":"https:\/\/hed-g.me\/index.php?rest_route=\/wp\/v2\/posts\/24\/revisions\/62"}],"wp:attachment":[{"href":"https:\/\/hed-g.me\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hed-g.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hed-g.me\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}