網際網路與Linux應用 Week 4

linux network config

wget -O - https://url.ckcsc.net/6PMzGw | bash

基本網路概論

https://oj.ckcsc.net
^^^^^   ^^ ^^^^^^^^^
|||||   ||    域名
|||||   主機名
通訊協定

https://203.64.138.177:8000
^^^^^   ^^^^^^^^^^^^^^ ^^^^
通訊協定        IP       port


s10730440:password@mercury.cksh.tp.edu.tw
^^^^^^^^^ ^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^
   帳號      密碼      主機名/IP(port)

指令

ping

$ ping oj.ckcsc.net
PING oj.ckcsc.net (104.31.79.104) 56(84) bytes of data.
64 bytes from 104.31.79.104 (104.31.79.104): icmp_seq=1 ttl=56 time=3.53 ms
64 bytes from 104.31.79.104 (104.31.79.104): icmp_seq=2 ttl=56 time=9.66 ms
64 bytes from 104.31.79.104 (104.31.79.104): icmp_seq=3 ttl=56 time=3.85 ms
64 bytes from 104.31.79.104 (104.31.79.104): icmp_seq=4 ttl=56 time=4.27 ms
^C
--- oj.ckcsc.net ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 3.530/5.331/9.662/2.515 ms

nmap

$ nmap oj.ckcsc.net

Starting Nmap 7.60 ( https://nmap.org ) at 2020-04-09 15:22 CST
Nmap scan report for oj.ckcsc.net (104.31.78.104)
Host is up (0.016s latency).
Other addresses for oj.ckcsc.net (not scanned): 104.31.79.104 2606:4700:3032::681f:4f68 2606:4700:3033::681f:4e68
Not shown: 990 filtered ports
PORT     STATE  SERVICE
21/tcp   open   ftp
25/tcp   open   smtp
80/tcp   open   http
110/tcp  open   pop3
113/tcp  closed ident
135/tcp  open   msrpc
143/tcp  open   imap
443/tcp  open   https
8010/tcp open   xmpp
8080/tcp open   http-proxy

Nmap done: 1 IP address (1 host up) scanned in 4.99 seconds

traceroute

$ traceroute oj.ckcsc.net
traceroute to oj.ckcsc.net (104.31.79.104), 30 hops max, 60 byte packets
 1  ip-70-0-0-1.brbnca.spcsdns.net (70.0.0.1)  0.881 ms  1.164 ms  1.344 ms
 2  gateway.cksh.tp.edu.tw (203.71.24.254)  2.830 ms  3.224 ms  3.607 ms
 3  * * *
 4  163.28.1.1 (163.28.1.1)  5.567 ms  9.860 ms  11.404 ms
 5  192.192.61.82 (192.192.61.82)  7.743 ms  13.051 ms  16.107 ms
 6  192.192.61.233 (192.192.61.233)  17.772 ms  18.614 ms  17.677 ms
 7  192.192.61.57 (192.192.61.57)  18.269 ms 192.192.61.58 (192.192.61.58)  16.888 ms  17.382 ms
 8  39-222-163-203-static.tpix.net.tw (203.163.222.39)  17.687 ms  16.212 ms  14.607 ms
 9  104.31.79.104 (104.31.79.104)  12.127 ms  11.951 ms  10.485 ms

mtr

$ mtr oj.ckcsc.net

mtr

tcpdump

$ sudo tcpdump 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlp3s0b1, link-type EN10MB (Ethernet), capture size 262144 bytes
17:04:28.534588 IP ip-70-0-4-24.brbnca.spcsdns.net.36278 > 163.28.5.33.http: Flags [.], ack 2021100217, win 501, options [nop,nop,TS val 3184001230 ecr 23738688], length 0
17:04:28.534649 IP ip-70-0-4-24.brbnca.spcsdns.net.36280 > 163.28.5.33.http: Flags [.], ack 1800572197, win 501, options [nop,nop,TS val 3184001230 ecr 23738688], length 0
17:04:28.535539 IP 163.28.5.33.http > ip-70-0-4-24.brbnca.spcsdns.net.36278: Flags [.], ack 1, win 58, options [nop,nop,TS val 23739712 ecr 3183898954], length 0
17:04:28.535986 IP ip-70-0-4-24.brbnca.spcsdns.net.42867 > earth.cksh.tp.edu.tw.domain: 14225+ [1au] PTR? 33.5.28.163.in-addr.arpa. (53)
17:04:28.536118 IP 163.28.5.33.http > ip-70-0-4-24.brbnca.spcsdns.net.36280: Flags [.], ack 1, win 58, options [nop,nop,TS val 23739712 ecr 3183898975], length 0
17:04:28.544649 IP earth.cksh.tp.edu.tw.domain > ip-70-0-4-24.brbnca.spcsdns.net.42867: 14225 NXDomain 0/1/1 (115)
17:04:28.544833 IP ip-70-0-4-24.brbnca.spcsdns.net.42867 > earth.cksh.tp.edu.tw.domain: 14225+ PTR? 33.5.28.163.in-addr.arpa. (42)
17:04:28.550589 IP ip-70-0-4-24.brbnca.spcsdns.net.52903 > earth.cksh.tp.edu.tw.domain: 9966+ [1au] PTR? 3.138.64.203.in-addr.arpa. (54)
17:04:28.552329 IP earth.cksh.tp.edu.tw.domain > ip-70-0-4-24.brbnca.spcsdns.net.52903: 9966* 1/0/1 PTR earth.cksh.tp.edu.tw. (88)
^C
9 packets captured
12 packets received by filter
3 packets dropped by kernel

curl

$ curl https://oj.ckcsc.net/api/contest?id=10
{
    "error": null,
    "data": {
        "id": 10,
        "created_by": {
            "id": 6,
            "username": "daniel920712",
            "real_name": null
        },
        "status": "-1",
        "contest_type": "Public",
        "title": "108\u5b78\u5e74\u4e0a\u5b78\u671fAPCS\u73ed10\u6708\u8cfd",
        "description": "<p>1:\u6bd4\u8cfd\u6642\u9593(\u5f97\u8996\u60c5\u6cc1\u8abf\u6574):10/25 1620-10/27 2400</p><p>2:\u672c\u6b21\u6bd4\u8cfd\u4f54\u7e3d\u6210\u7e3e25%<br /></p><p>3:\u6bd4\u8cfd&\u5f97\u734e\u8cc7\u683c:\u6210\u96fb32&33\u975e\u5e79\u90e8\u8005\uff0c\u4e14\u4e09\u73ed\u5206\u958b\u547d\u984c\uff0c\u8a08\u5206</p><p>4:\u6bd4\u8cfd\u984c\u6578:6\u984c</p><p>5:\u6bd4\u8cfd\u8cfd\u5236:OI\u8cfd\u5236(\u6709\u90e8\u5206\u5206)</p><p>6:\u547d\u984c\u7bc4\u570d:\u904b\u7b97\uff0c\u689d\u4ef6\uff0c\u8ff4\u5708\uff0c\u9663\u5217\uff0c\u5b57\u4e32</p><p>7:\u6bd4\u8cfd\u984c\u76ee\u6216\u7d50\u679c\u5982\u6709\u7591\u7fa9\uff0c\u8acb\u4ee5\u63d0\u554f\u8868\u55ae\u63d0\u554f(\u8868\u55ae\u53ca\u56de\u5fa9\u7db2\u5740\u5c07\u65bc\u6bd4\u8cfd\u7db2\u7ad9\u516c\u5e03)</p><p>8:\u6bd4\u8cfd\u671f\u9593\u5f97\u53c3\u8003\u8cc7\u6599\uff0c\u70ba\u4e0d\u5f97\u6709\u6284\u8972\u6216\u60e1\u610f\u5e72\u64fejudge\u904b\u4f5c\u4e4b\u60c5\u5f0f\uff0c\u9055\u8005\u4e3b\u8fa6\u55ae\u4f4d\u5f97\u64a4\u92b7\u8cc7\u683c</p><p>9:\u6bd4\u8cfd\u5b98\u7db2:oj.ckcsc.net</p><p>10:\u547d\u984c\u7fa4:\u6210\u96fb\u767e\u5341\u6559\u5b78\u7fa4</p><p>11:\u5982\u6709\u5176\u4ed6\u672a\u76e1\u4e8b\u5b9c\uff0c\u4e3b\u8fa6\u55ae\u4f4d\u5f97\u66f4\u6539\u898f\u5247</p><p>\u5099\u8a3b:\u5982\u5e33\u865f\u672a\u586b\u771f\u5be6\u59d3\u540d\u5c0e\u81f4\u7121\u6cd5\u8fa8\u8b58\uff0c\u4e3b\u8fa6\u55ae\u4f4d\u5f97\u53d6\u6d88\u8cc7\u683c</p>",
        "real_time_rank": true,
        "rule_type": "OI",
        "start_time": "2019-10-25T08:20:00Z",
        "end_time": "2019-10-27T15:59:59Z",
        "create_time": "2019-10-24T13:43:11.370765Z",
        "last_update_time": "2019-12-17T04:46:04.984015Z",
        "now": "2020-04-09T09:15:31.414981Z"
    }
}
Select a repo