请大家执行 nslookup 1.2.3.4. (注意后面多了个点),结果是咋样的?

[clino]

我这里试过如果是 8.8.8.8 会报:
'''
Server: 8.8.8.8
Address: 8.8.8.8#53

** server can't find 1.2.3.4.: NXDOMAIN
'''

如果是家里联通宽带自动获得的dns server,结果是:
'''
Server: 218.104.128.106
Address: 218.104.128.106#53

Non-authoritative answer:
Name: 1.2.3.4
Address: 220.250.64.19
'''

[013231]

Server: 8.8.8.8
Address: 8.8.8.8#53

** server can't find 1.2.3.4.: NXDOMAIN

[hanai]

服务器: my.router
Address: 192.168.1.1

*** my.router 找不到 1.2.3.4.: Non-existent domain

[fanzeyi]

$ nslookup 1.2.3.4.
Server: 114.114.114.114
Address: 114.114.114.114#53

** server can't find 1.2.3.4.: NXDOMAIN

[no2x]

>nslookup 1.2.3.4
Server: UnKnown
Address: 168.95.1.1

*** UnKnown can't find 1.2.3.4: No response from server

[9hills]

用联通dns时，不存在的域名会指向联通的导航页，浏览器里输一下就知道了

[claliu]

执行 set type=ptr 才有意义呀, 而且并不是每个 IP 地址都有对应的 PTR 记录.
例如:

8.8.8.8.in-addr.arpa name = google-public-dns-a.google.com.
114.114.114.114.in-addr.arpa name = public1.114dns.com.


( http://en.wikipedia.org/wiki/List_of_DNS_record_types )

[clino]

@no2x 注意是 1.2.3.4. 不是 1.2.3.4

[jkeylu]

C:\Users\jKey>nslookup 1.2.3.4.
服务器: UnKnown
Address: 192.168.1.1

非权威应答:
名称: 1.2.3.4
Address: 180.168.41.175

[no2x]

>nslookup 1.2.3.4.
Server: dns.hinet.net
Address: 168.95.1.1

*** dns.hinet.net can't find 1.2.3.4.: Non-existent domain

[freeznet]

nslookup 1.2.3.4.
Server: 10.50.8.95
Address: 10.50.8.95#53

** server can't find 1.2.3.4.: NXDOMAIN

[clino]

看起来大部分人还是正常的(NXDOMAIN),我听别人说南方运营商的都会返回ip

[xavierskip]

会返回114导航。

[doskoi]

用v2ex的
nslookup non.existent.domain
Server: 178.79.131.110
Address: 178.79.131.110#53

Non-authoritative answer:
Name: non.existent.domain
Address: 178.79.131.110

用个google的
nslookup non.existent.domain
Server: 8.8.8.8
Address: 8.8.8.8#53

** server can't find non.existent.domain: NXDOMAIN


通过DNS查询不存在的域名的返回可以判断DNS污染
具体在
https://code.google.com/p/openwrt-gfw/wiki/AntiDNSPoisoning