1) On utilise la commande ncat -ul 50000 sur un premier terminal. sur un autre terminal on utilise la commande ss -lnu [solar@salle231-04 TP14]$ ss -lun State Recv-Q Send-Q Local Address:Port Peer Address:Port UNCONN 0 0 0.0.0.0:5353 0.0.0.0:* UNCONN 0 0 0.0.0.0:5355 0.0.0.0:* UNCONN 0 0 127.0.0.54:53 0.0.0.0:* UNCONN 0 0 127.0.0.53%lo:53 0.0.0.0:* UNCONN 0 0 172.16.2.91%eno1:68 0.0.0.0:* UNCONN 0 0 172.17.255.255:137 0.0.0.0:* UNCONN 0 0 172.17.0.1:137 0.0.0.0:* UNCONN 0 0 172.16.255.255:137 0.0.0.0:* UNCONN 0 0 172.16.2.91:137 0.0.0.0:* UNCONN 0 0 0.0.0.0:137 0.0.0.0:* UNCONN 0 0 172.17.255.255:138 0.0.0.0:* UNCONN 0 0 172.17.0.1:138 0.0.0.0:* UNCONN 0 0 172.16.255.255:138 0.0.0.0:* UNCONN 0 0 172.16.2.91:138 0.0.0.0:* UNCONN 0 0 0.0.0.0:138 0.0.0.0:* UNCONN 0 0 0.0.0.0:50000 0.0.0.0:* UNCONN 0 0 [::]:5353 [::]:* UNCONN 0 0 [::]:5355 [::]:* UNCONN 0 0 [fe80::e654:e8ff:fea1:a2e8]%eno1:546 [::]:* UNCONN 0 0 [::]:50000 [::]:* 2) dd if=/dev/urandom of=ft-file.dat bs=1024 count=9 9+0 records in 9+0 records out 9216 bytes (9.2 kB, 9.0 KiB) copied, 0.0083619 s, 1.1 MB/s ls -lh ft-file.dat -rw-r--r-- 1 solar students23 9.0K Mar 12 14:52 ft-file.dat 3) ncat -lu 50000 > resultat ncat 192.16.2.91 < ft-file.dat a la fin dans resultat on a la même chose que tu sur le fichier ft-file.dat -rw-r--r-- 1 solar info-etu-but-2024 9216 Feb 11 17:06 resultat 4. tcpdump -tn "tcp and port 50000 and not arp" a) tcpdump: verbose output suppressed, use -v[v]... for full protocol decode listening on eno1, link-type EN10MB (Ethernet), snapshot length 262144 bytes ^C 0 packets captured 0 packets received by filter 0 packets dropped by kernel b) tcpdump: verbose output suppressed, use -v[v]... for full protocol decode listening on eno1, link-type EN10MB (Ethernet), snapshot length 262144 bytes ^C 0 packets captured 0 packets received by filter 0 packets dropped by kernel c) tcpdump: verbose output suppressed, use -v[v]... for full protocol decode listening on eno1, link-type EN10MB (Ethernet), snapshot length 262144 bytes ^C 0 packets captured 0 packets received by filter 0 packets dropped by kernel 6) serveur : -terminal 1: ncat -ul 50000 -terminal 2: tcpdump -i eno1 "udp and port 50000" tcpdump: verbose output suppressed, use -v[v]... for full protocol decode listening on eno1, link-type EN10MB (Ethernet), snapshot length 262144 bytes 16:40:07.467945 IP salle229-02.iut-fbleau.fr.52428 > salle229-01.iut-fbleau.fr.50000: UDP, length 8192 16:40:07.468060 IP salle229-02.iut-fbleau.fr.52428 > salle229-01.iut-fbleau.fr.50000: UDP, length 1024 Client : terminal 1: tcpdump -i eno1 "udp and port 50000" terminal 2: ncat -u [ip] 500000 < ft-file.dat 7) Il y a 2 paquet, un de 8192 et un autre de 1024. II) 1) which traceroute which: no traceroute in (/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/opt/android-sdk/platform-tools:/opt/android-sdk/tools:/opt/android-sdk/tools/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl) which tracepath /usr/bin/tracepath cela signifie que tracepath existe et non traceroute 2) terminal 1: tcpdump -i eno1 -nlvt "host 172.16.2.102 and host not 172.16.3.30 and host not 172.16.3.31 and not arp and not tcp" > tracepath-trace.txt terminal 2: tracepath 8.8.8.8 -4 -n -p 33434 terminal 2: 1?: [LOCALHOST] pmtu 1500 1: 172.16.1.254 0.570ms 1: 172.16.1.254 0.544ms 2: 37.58.131.238 0.876ms 3: 100.65.0.27 3.015ms 4: 100.121.1.230 4.487ms 5: no reply 6: 108.170.255.139 4.279ms asymm 9 7: 142.250.234.43 3.753ms asymm 9 8: 8.8.8.8 3.383ms reached Resume: pmtu 1500 hops 8 back 12 terminal 1: IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33434: UDP, length 1472 IP (tos 0xc0, ttl 64, id 2195, offset 0, flags [none], proto ICMP (1), length 576) 172.16.1.254 > 172.16.2.102: ICMP time exceeded in-transit, length 556 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33434: UDP, length 1472 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33435: UDP, length 1472 IP (tos 0xc0, ttl 64, id 2196, offset 0, flags [none], proto ICMP (1), length 576) 172.16.1.254 > 172.16.2.102: ICMP time exceeded in-transit, length 556 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33435: UDP, length 1472 IP (tos 0x0, ttl 2, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33436: UDP, length 1472 IP (tos 0x0, ttl 254, id 0, offset 0, flags [none], proto ICMP (1), length 56) 37.58.131.238 > 172.16.2.102: ICMP time exceeded in-transit, length 36 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33436: UDP, length 1472 IP (tos 0x0, ttl 3, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33437: UDP, length 1472 IP (tos 0x0, ttl 253, id 13569, offset 0, flags [none], proto ICMP (1), length 96) 100.65.0.27 > 172.16.2.102: ICMP time exceeded in-transit, length 76 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33437: UDP, length 1472 IP (tos 0x0, ttl 4, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33438: UDP, length 1472 IP (tos 0x0, ttl 252, id 33397, offset 0, flags [none], proto ICMP (1), length 96) 100.121.1.230 > 172.16.2.102: ICMP time exceeded in-transit, length 76 IP (tos 0x0, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33438: UDP, length 1472 IP (tos 0x0, ttl 5, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33439: UDP, length 1472 IP (tos 0x0, ttl 5, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33440: UDP, length 1472 IP (tos 0x0, ttl 5, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33441: UDP, length 1472 IP (tos 0x0, ttl 6, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33442: UDP, length 1472 IP (tos 0x0, ttl 56, id 56705, offset 0, flags [none], proto ICMP (1), length 576) 142.251.77.75 > 172.16.2.102: ICMP time exceeded in-transit, length 556 IP (tos 0x80, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33442: UDP, length 1472 IP (tos 0x0, ttl 7, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33443: UDP, length 1472 IP (tos 0x0, ttl 56, id 55663, offset 0, flags [none], proto ICMP (1), length 576) 142.251.64.125 > 172.16.2.102: ICMP time exceeded in-transit, length 556 IP (tos 0x80, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33443: UDP, length 1472 IP (tos 0x0, ttl 8, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33444: UDP, length 1472 IP (tos 0x0, ttl 117, id 0, offset 0, flags [none], proto ICMP (1), length 56) 8.8.8.8 > 172.16.2.102: ICMP 8.8.8.8 udp port 33444 unreachable, length 36 IP (tos 0x80, ttl 1, id 0, offset 0, flags [DF], proto UDP (17), length 1500) 172.16.2.102.37566 > 8.8.8.8.33444: UDP, length 1472 ^C19 packets captured 20 packets received by filter 0 packets dropped by kernel 3. Le -n permet d'écrire principalement les adresse IP en format numérique. dig www.google.fr 142.250.179.67 tracepath 142.250.179.67 -4 4. a) grep "ICMP time" tracepath-trace.txt b) grep "ttl" tracepath-trace.txt