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所有無效主機都會解析為“com.org”

tag-icon • tag-icon linux dns
所有無效主機都會解析為“com.org” 
vi@vi-server:~$ nslookup nonexistent.itransition.com
Server:         8.8.8.8
Address:        8.8.8.8#53

** server can't find nonexistent.itransition.com: NXDOMAIN

vi@vi-server:~$ cat /etc/resolv.conf 
nameserver 8.8.8.8

它不存在。同樣的結果來自dig nonexistent.itransition.com.

vi@vi-server:~$ ping nonexistent.itransition.com
PING nonexistent.itransition.com.org (216.234.246.153) 56(84) bytes of data.
64 bytes from 99.f6.ead8.static.theplanet.com (216.234.246.153): icmp_seq=1 ttl=46 time=128 ms
64 bytes from 99.f6.ead8.static.theplanet.com (216.234.246.153): icmp_seq=2 ttl=46 time=128 ms

它捕獲所有無效主機名稱？為什麼？如何預防？

追蹤輸出：

$ strace -s1024 ping nonexistent.itransition.com
execve("/bin/ping", ["ping", "nonexistent.itransition.com"], [/* 18 vars */]) = 0
...
socket(PF_INET, 0x802 /* SOCK_??? */, IPPROTO_IP) = 3
connect(3, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("8.8.8.8")}, 16) = 0
...
send(3, "\6\340\1\0\0\1\0\0\0\0\0\0\vnonexistent\vitransition\3com\0\0\1\0\1"..., 45, MSG_NOSIGNAL) = 45
...
recvfrom(3, "\6\340\201\203\0\1\0\0\0\1\0\0\vnonexistent\vitransition\3com\0\0\1\0\1\300\30\0\6\0\1\0\0\5\270\0;\3ns1\fworldwidedns\3net\0\16it@itransition\300$w\336\23.\0\0T`\0\0*0\0\t:\200\0\0\250\300"..., 1024, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("8.8.8.8")}, [16]) send(3, "6c\1\0\0\1\0\0\0\0\0\0\vnonexistent\vitransition\3com\3org\0\0\1\0\1"..., 49, MSG_NOSIGNAL) = 49= 116
close(3)            

# Why it tries .com.org after that?
socket(PF_INET, 0x802 /* SOCK_??? */, IPPROTO_IP) = 3
connect(3, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("8.8.8.8")}, 16) = 0
...
send(3, "6c\1\0\0\1\0\0\0\0\0\0\vnonexistent\vitransition\3com\3org\0\0\1\0\1"..., 49, MSG_NOSIGNAL) = 49
...
recvfrom(3, "6c\201\200\0\1\0\1\0\0\0\0\vnonexistent\vitransition\3com\3org\0\0\1\0\1\300\f\0\1\0\1\0\0\f\304\0\4\330\352\366\231"..., 1024, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("8.8.8.8")}, [16]) = 65
close(3)

答案1

嘗試一下ICSI 網路分析儀。它是一個 Java 應用程序，可以測試您的 Internet 連接是否有問題跡象。您的 ISP 可能會將您的 DNS 查找重新導向到自己的伺服器以銷售廣告或出於其他原因。

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