49. Linux shell commands, host, NSlookup, and dig

1. Host

1) DNS lookup Utility

Host option {name} [server]

Use/etc/resolv. confMedium serverAs the source of the DNS server

2) Option

-A: lists detailed host name settings for this host.

3) Example

Host www.google.com

2. NSLookup-

Query Internet name servers interactively. Similar to host.

NSLookup [-query = [type] [hostname | IP]

Types include Mx and cname.

NSLookup-query = Mx www.google.com

3. Dig

1) Dig [@ dns_server] [Option] Name [type]

Dns_server is a DNS server, and the default DNS server (/etc/resolv. conf nameserver); Type specifies the query type. The available value is any | A | MX | SOA | PTR | TXT | NS | cname.

2) Option

-X reverse resolution: queries the PTR record of the specified IP address (that is, the domain name)

-B: Specifies the source IP address used for sending the query.

3) Example

Dig-x 192.168.0.1

Dig www.baidu.com

Reference

[1] A Brief Introduction to dig

Http://hi.baidu.com/test/blog/item/b728c65c1ad28c4bfbf2c091.html

[2]Http://linux.vbird.org/linux_server/0140networkcommand.php#host

[3] Detailed dig reference

Http://bbs.linuxsky.org/thread-3054-1-1.html