BINDDNS internal training course 3

Start of Authority authorization Start of SOA marking area data, define the parameter Name Server that affects the entire area

NS indicates the Domain Name Server

Address

A. Convert the host name to the address

Pointer PTR to convert the address to the Host Name

Mail Exchange MX indicates the location where the Mail sent to a given domain name should be sent

Canonical Name regular Name CNAME defined host Name alias

HOST information HINFO depicts HOST hardware and operating system information

Wellknown Service famous Service WKS announcement NETWORK Service

DNS uses MX records for mail routing. It specifies that the mail server of the domain name either processes or forwards emails related to the domain name. mail Processing refers to sending it to the individual associated with the address, and forward mail refers to sending it to its final destination through SMTP protocol. To prevent mail routing, the MX record has a special parameter besides the Domain Name of the email exchanger: Priority value. the priority value is an unsigned integer from 0 to 65535, which gives the priority level of the email exchanger. The priority value itself is not important. The key lies in its relative size with the priority value of other mail exchangers. The smaller the priority value, the higher the priority. An email always tries to pass the email to the email exchanger with the smallest priority value. If the email fails, it tries to pass the email to the email exchanger with a higher priority value. An email is always sent to an email exchanger with the same priority. Note that hosts listed as email switches must have address records.

For example:

Mail A 172.16.0.3

MX 10 mail.test.com.

5.Management tools

5.1 dig

Named. the ca file is used to tell your server where you can find the domain server in the root domain. This file must be correct. Generally, this file will not change, but it cannot be guaranteed that it will not change. It is best to synchronize every one or two months. Run the following command to obtain the new named. ca file:

Dig @ a.root-servers.net. ns>/var/named. ca

5.2 ndc

The ndc command is used by the system administrator to manage operations on the Domain Server. You can enter ndc help in the terminal for help.

Ndc restart is used to restart the named process;

Ndc reload is used to load new databases.

5.3 nslookup

Nslookup is a command used to query domain name information. It is divided into two modes: Interactive Mode and non-interactive mode.

Non-interactive mode: nslookup www.zhuhai.gd.cn

Interactive Mode: nslookup

Note: When nslookup is used for query, 'non-authoritative answer: 'is displayed, indicating that this query is not performed outside the network, but is performed in the cache area to find and locate the data.

In addition to querying a single host, the interactive mode can also query any type of DNS records and transmit the information of the entire region of a domain. When called without parameters, nslookup displays the name server it uses and enters the interaction mode.

At the '>' prompt, you can type any domain name you want to query. By default, it requests A records, which contain IP addresses related to domain names.

You can change this type by issuing 'set type = type'. Here type is the resource record name described above, or ANY.

For example, you can have the following conversation with it:

$ Nslookup

Default Name Server: rs10.hrz.th-darmstadt.de

Address: 130.83.56.60

> Sunsite.unc.edu

Name Server: rs10.hrz.th-darmstadt.de

Address: 130.83.56.60

Non-authoritative answer:

Name: sunsite.unc.edu

Address: 152.2.22.81

If you want to query a name with no corresponding IP address, but other records can be found in the DNS database, nslookup will return an error message saying 'no type A records found' ('no type A record discover ').

However, you can run the 'set type' command to query other records not of type. For example, to obtain the SOA record of unc.edu, you must issue:

> Unc.edu

* ** No address (A) records available for unc.edu

Name Server: rs10.hrz.th-darmstadt.de

Address: 130.83.56.60

> Set type = SOA

> Unc.edu

Name Server: rs10.hrz.th-darmstadt.de

Address: 130.83.56.60

Non-authoritative answer:

Unc.edu

Origin = ns.unc.edu

Mail addr = shava.ns.unc.edu

Serial = 930408

Refresh = 28800 (8 hours)

Retry = 3600 (1 hour)

Expire = 1209600 (14 days)

Minimum ttl = 86400 (1 day)

Authoritative answers can be found from:

UNC. EDU nameserver = SAMBA. ACS. UNC. EDU

SAMBA. ACS. UNC. EDU internet address = 128.109.157.30

You can query MX records in the same way. Using an ANY type, all resource records associated with a given name are returned.

> Set type = MX

> Unc.edu

Non-authoritative answer:

Unc.edu preference = 10, mail exchanger = lambada.oit.unc.edu

Lambada.oit.unc.edu internet address = 152.2.22.80

Authoritative answers can be found from:

UNC. EDU nameserver = SAMBA. ACS. UNC. EDU

SAMBA. ACS. UNC. EDU internet address = 128.109.157.30

In addition to debugging, an actual application of nslookup is to obtain the current list of root name servers for the named. ca file.

You can query all NS type records related to the root domain:

> Set type = NS

>.

Name Server: fb0430.mathematik.th-darmstadt.de

Address: 130.83.2.30

Non-authoritative answer:

(Root) nameserver = NS. INTERNIC. NET

(Root) nameserver = AOS. ARL. ARMY. MIL

(Root) nameserver = C. NYSER. NET

(Root) nameserver = TERP. UMD. EDU

(Root) nameserver = NS. NASA. GOV

(Root) nameserver = NIC. NORDU. NET

(Root) nameserver = NS. NIC. DDN. MIL

Authoritative answers can be found from:

(Root) nameserver = NS. INTERNIC. NET

(Root) nameserver = AOS. ARL. ARMY. MIL

(Root) nameserver = C. NYSER. NET

(Root) nameserver = TERP. UMD. EDU

(Root) nameserver = NS. NASA. GOV

(Root) nameserver = NIC. NORDU. NET

(Root) nameserver = NS. NIC. DDN. MIL

NS. INTERNIC. NET internet address = 198.41.0.4

AOS. ARL. ARMY. MIL internet address = 128.63.4.82

AOS. ARL. ARMY. MIL internet address = 192.5.25.82

AOS. ARL. ARMY. MIL internet address = 26.3.0.29

C. NYSER. NET internet address = 192.33.4.12

TERP. UMD. EDU internet address = 128.8.10.90

NS. NASA. GOV internet address = 128.102.16.10

NS. NASA. GOV internet address = 192.52.195.10

NS. NASA. GOV internet address = 45.13.10.121

NIC. NORDU. NET internet address = 192.36.148.17

NS. NIC. DDN. MIL internet address = 192.112.36.4

The complete nslookup command set can be obtained through the help Command in nslookup.

Article entry: csh responsible editor: csh