host -t A nfs:
nfs.foo.bar has address *.*.*.151
cat /etc/nsswitch.conf
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.
passwd: compat
group: compat
shadow: compat
gshadow: files
hosts: files mdns4_minimal [NOTFOUND=return] dns
networks: files
protocols: db files
services: db files
ethers: db files
rpc: db files
netgroup: nis
sudo tcpdump -c 100 -vvveni <Interface> port 53
Aaaha! Er fragt zweimal den Nameserver, der antwortet nicht (sagt mir aber, der Dienst liefe...) und fragt dann die Fritzbox, die die alte IP herausgibt (aber nirgends unter Heimnetz aufführt)...
15:00:31.933224 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 1306, offset 0, flags [DF], proto UDP (17), length 84)
*.*.*.121.44857 > 8.8.8.8.53: [udp sum ok] 19051+ A? profile.accounts.firefox.com.foo.bar. (56)
15:00:31.933237 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 1307, offset 0, flags [DF], proto UDP (17), length 84)
*.*.*.121.44857 > 8.8.8.8.53: [udp sum ok] 48489+ AAAA? profile.accounts.firefox.com.foo.bar. (56)
15:00:32.250344 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 1332, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.38282 > 8.8.8.8.53: [udp sum ok] 19058+ A? 0.ubuntu.pool.ntp.org. (39)
15:00:32.250359 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 1333, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.38282 > 8.8.8.8.53: [udp sum ok] 42203+ AAAA? 0.ubuntu.pool.ntp.org. (39)
15:00:32.251168 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 22823, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.58851 > *.*.*.12.53: [udp sum ok] 31941+ A? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.251177 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 22824, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.58851 > *.*.*.12.53: [udp sum ok] 7370+ AAAA? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.251883 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 1334, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.42441 > 8.8.8.8.53: [udp sum ok] 31941+ A? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.251894 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 1335, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.42441 > 8.8.8.8.53: [udp sum ok] 7370+ AAAA? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.252644 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 22825, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.38706 > *.*.*.12.53: [udp sum ok] 31941+ A? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.252654 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 22826, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.38706 > *.*.*.12.53: [udp sum ok] 7370+ AAAA? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.253324 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 1336, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.60610 > 8.8.8.8.53: [udp sum ok] 31941+ A? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.253335 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 91: (tos 0x0, ttl 64, id 1337, offset 0, flags [DF], proto UDP (17), length 77)
*.*.*.121.60610 > 8.8.8.8.53: [udp sum ok] 7370+ AAAA? 0.ubuntu.pool.ntp.org.foo.bar. (49)
15:00:32.254922 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 22827, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.46173 > *.*.*.12.53: [udp sum ok] 7354+ A? 1.ubuntu.pool.ntp.org. (39)
15:00:32.254932 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 22828, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.46173 > *.*.*.12.53: [udp sum ok] 60604+ AAAA? 1.ubuntu.pool.ntp.org. (39)
15:00:32.255698 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 10141, offset 0, flags [DF], proto UDP (17), length 67)
15:00:32.255708 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 10142, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.59268 > *.*.*.1.53: [udp sum ok] 60604+ AAAA? 1.ubuntu.pool.ntp.org. (39)
15:00:32.290894 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 145: (tos 0x0, ttl 64, id 29379, offset 0, flags [none], proto UDP (17), length 131)
*.*.*.1.53 > *.*.*.121.59268: [udp sum ok] 7354 q: A? 1.ubuntu.pool.ntp.org. 4/0/0 1.ubuntu.pool.ntp.org. [2m30s] A 46.165.212.205, 1.ubuntu.pool.ntp.org. [2m30s] A 78.46.53.8, 1.ubuntu.pool.ntp.org. [2m30s] A 90.187.7.5, 1.ubuntu.pool.ntp.org. [2m30s] A 78.46.37.9 (103)
15:00:32.291841 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 136: (tos 0x0, ttl 64, id 29380, offset 0, flags [none], proto UDP (17), length 122)
*.*.*.1.53 > *.*.*.121.59268: [udp sum ok] 60604 q: AAAA? 1.ubuntu.pool.ntp.org. 0/1/0 ns: pool.ntp.org. [19m47s] SOA i.ntpns.org. hostmaster.pool.ntp.org. 1487080262 5400 5400 1209600 3600 (94)
15:00:32.292132 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 22830, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.59655 > *.*.*.12.53: [udp sum ok] 7855+ A? 3.ubuntu.pool.ntp.org. (39)
15:00:32.292142 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 22831, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.59655 > *.*.*.12.53: [udp sum ok] 64691+ AAAA? 3.ubuntu.pool.ntp.org. (39)
15:00:34.455627 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 78: (tos 0x0, ttl 64, id 23187, offset 0, flags [DF], proto UDP (17), length 64)
*.*.*.121.35604 > *.*.*.12.53: [udp sum ok] 13815+ A? nfs.foo.bar. (36)
15:00:34.456172 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 78: (tos 0x0, ttl 64, id 10674, offset 0, flags [DF], proto UDP (17), length 64)
*.*.*.121.51142 > *.*.*.1.53: [udp sum ok] 13815+ A? nfs.foo.bar. (36)
15:00:34.457099 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 124: (tos 0x0, ttl 64, id 29381, offset 0, flags [none], proto UDP (17), length 110)
*.*.*.1.53 > *.*.*.121.51142: [udp sum ok] 13815* q: A? nfs.foo.bar. 1/1/1 nfs.foo.bar. [9s] A *.*.*.151 ns: nfs.foo.bar. [9s] NS foo.bar. ar: foo.bar. [9s] A *.*.*.1 (82)
15:00:37.297203 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 11315, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.37228 > *.*.*.1.53: [udp sum ok] 7855+ A? 3.ubuntu.pool.ntp.org. (39)
15:00:37.297217 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 81: (tos 0x0, ttl 64, id 11316, offset 0, flags [DF], proto UDP (17), length 67)
*.*.*.121.37228 > *.*.*.1.53: [udp sum ok] 64691+ AAAA? 3.ubuntu.pool.ntp.org. (39)
15:00:37.457272 74:d4:35:0c:30:01 > b8:27:eb:fb:fa:ef, ethertype IPv4 (0x0800), length 87: (tos 0x0, ttl 64, id 23592, offset 0, flags [DF], proto UDP (17), length 73)
*.*.*.121.59409 > *.*.*.12.53: [udp sum ok] 40301+ PTR? 121.*.*.*.in-addr.arpa. (45)
15:00:37.457848 74:d4:35:0c:30:01 > 24:65:11:dc:26:7b, ethertype IPv4 (0x0800), length 87: (tos 0x0, ttl 64, id 11356, offset 0, flags [DF], proto UDP (17), length 73)
*.*.*.121.49515 > *.*.*.1.53: [udp sum ok] 40301+ PTR? 121.*.*.*.in-addr.arpa. (45)
15:00:37.461043 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 145: (tos 0x0, ttl 64, id 29382, offset 0, flags [none], proto UDP (17), length 131)
*.*.*.1.53 > *.*.*.121.37228: [udp sum ok] 7855 q: A? 3.ubuntu.pool.ntp.org. 4/0/0 3.ubuntu.pool.ntp.org. [2m30s] A 78.46.107.140, 3.ubuntu.pool.ntp.org. [2m30s] A 62.116.130.3, 3.ubuntu.pool.ntp.org. [2m30s] A 88.198.12.78, 3.ubuntu.pool.ntp.org. [2m30s] A 78.47.226.8 (103)
15:00:37.461913 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 150: (tos 0x0, ttl 64, id 29383, offset 0, flags [none], proto UDP (17), length 136)
*.*.*.1.53 > *.*.*.121.49515: [udp sum ok] 40301* q: PTR? 121.*.*.*.in-addr.arpa. 1/1/1 121.*.*.*.in-addr.arpa. [9s] PTR Rechner3.foo.bar. ns: 121.*.*.*.in-addr.arpa. [9s] NS foo.bar. ar: foo.bar. [9s] A *.*.*.1 (108)
15:00:37.463026 24:65:11:dc:26:7b > 74:d4:35:0c:30:01, ethertype IPv4 (0x0800), length 136: (tos 0x0, ttl 64, id 29384, offset 0, flags [none], proto UDP (17), length 122)
*.*.*.1.53 > *.*.*.121.37228: [udp sum ok] 64691 q: AAAA? 3.ubuntu.pool.ntp.org. 0/1/0 ns: pool.ntp.org. [19m41s] SOA i.ntpns.org. hostmaster.pool.ntp.org. 1487080262 5400 5400 1209600 3600 (94)
Wie zwinge ich jetzt den Nameserver zur Antwort...?