nslookup command Summary
definition of 0.nslookupNslookup is a command-line tool that Microsoft publishes to detect and debug DNS servers. Two modes: one. Non-interactive mode nslookup–qt= type target domain name (the default query type is a address record IPV4) nslookup-qt= Type the destination domain name specifies the DNS server IP or domain name two. Interactive modenslookup "Enter" Enter interactive line modeSet qt= type Set the query type, default to a
IP or domain name set qt= has a type Toggle Query Type Help or? View Help
Exit Exit nslookup interactive mode
Query type: A address record (IPV4) AAAA address record (Ipv6) AFSDB Andrew File system database server record (not understood) Atma ATM address record (not ATM) CNAME alias record Hinfo hardware configuration record, including CPU, Operating System Information ISDN domain name corresponding ISDN number MB hold the server for the specified mailbox MG mail group record Minfo Mail Group and mailbox information record Mr Renamed mailbox record MX mail server record NS name server record PTR reverse record (from IP address interpret domain name) RP owner record RT Routing penetration record (not understood) SRV TCP server information record (will be of great use) TXT domain corresponding to the text information x25 domain name corresponding to the X. address record
1. Forward parsing- resolves a domain name to an IP address Query Type:a(can be omitted) Example: >nslookup www.163.com--------------------------Parsing-------------------------non-authoritative response (non-authoritative answer):
assuming that a DNS server does not have record information for the domain name test.com, when a client requests for test.com domain name information through it, the DNS server actually stores the DNS of this record information from test company by iterating recursively The server obtains test.com's domain name information, feeds back to the requesting client, and puts Test.com's record information in its own cache for a period of time, and when a client requests test.com domain name resolution, this DNS The server fetches the client directly from its own cache, which is called a "non-authoritative answer", in short, a "non-authoritative answer" to the domain name resolution answer that is obtained from the non-physical record store DNS server.
(name): 163.xdwscache.glb0.lxdns.com refers towww.163.com The actual host name record for the domain name. Addresses: AddressesThere are multiple records, that is, the 163.com domain name actually corresponds to multiple physical hosts,when a user accesses www.163.com, it is answered by one of the computers according to certain rules, which can effectively load balance the domain name. aliase: DNS record alias, convenient for us to remember
2. Reverse parsing-by IP address, resolving domain namesQuery Type:Examples of PTR reverse logging (interpreting domain names from IP addresses):nslookup-qt=ptr IP Address
3. Querying mail server informationUsed to view mail server information in the domain, this command allows you to view the IP list (if multiple mail servers) of the mail server corresponding to the domain, and the corresponding base level perference, where the number is lower and the priority level is higher. Query type: MX mail server record example: Nslookup-qt=mx mail.xxxx.com
4. View named server NSNS is a domain name corresponding to multiple servers, which server to the domain name and sub-records to parse.Query Type:NS Name Server Record Example:Nslookup-qt=ns baidu.com (remember not to take WWW)
5. View DNS Cache record save time-ttlTTL-the time that the cache is retained to indicate that the DNS record is cached on the DNS server. In the pursuit of resolution speed, the TTL value is larger, in the recent plan to change the IP address, the TTL value is smaller.
Example: Nslookup-debug www.baidu.com (This is not a query) reference and reference: http://blog.vsharing.com/BillMa/A1053860.html Online nslookup tool: http ://www.kloth.net/services/nslookup.php
From for notes (Wiz)
nslookup command Summary