nslookup query not working in Ubuntu

Question

I am trying to use the code nslookup -q=mx gmail.com to find the mail server of gmail.com, but its not working on my Ubuntu. I have tried it in windows and it works fine. I can't find out what the issue on Ubuntu. The command nslookup gmail.com works though. Here are the responses of both commands;

Response for: nslookup gmail.com

thisisppn@thisisppn-HP-15-Notebook-PC:~$ nslookup gmail.com
Server:     127.0.1.1
Address:    127.0.1.1#53

Non-authoritative answer:
Name:   gmail.com
Address: 216.58.196.5

Response for: nslookup -q=mx gmail.com

thisisppn@thisisppn-HP-15-Notebook-PC:~$ nslookup -q=mx gmail.com
;; connection timed out; no servers could be reached

Solution

After a quick chat, I noted that the DNS entries causing you to resolve your queries. Adding DNS entries to /etc/resolv.conf made me clear that it is indeed the DNS.

Ways of adding DNS entries listed below.

Adding additional entries to resolv.conf

Create a file under /etc/resolvconf/resolv.conf.d/ as tail and add them there.

sudo nano /etc/resolvconf/resolv.conf.d/tail

and add nameserver 8.8.8.8 (or your preferred DNS). Once done, just restart the network manager with:

sudo service network-manager restart

Adding through network-manager

Edit Connections -> select your network (wired/wireless) and Edit -> IPv4 Settings -> and select Automatic (DHCP) address only -> add under Additional DNS servers

Comments

[AzkerM]

Looks strange though. Can you type just nslookup and enter, then type set type=mx and enter, now just try gmail.com. let me know whether that works?

[Parthapratim Neog]

i know right, I even tried it out on a live server, its working fine. And Regarding your suggestion. Here is the response which is same. thisisppn@thisisppn-HP-15-Notebook-PC:~$ nslookup > set type=mx > gmail.com ;; connection timed out; no servers could be reached >

[AzkerM]

are you able to ping with an FQDN? what are your DNS servers? can you post an out put of cat /etc/resolv.conf & route -n.

[Parthapratim Neog]

@AzkerM here is the output, I put it up on pastebin for better view. pastebin.com/akNAnNhM

[Parthapratim Neog]

@AzkerM Not sure what a FQDN is, as I am really new to Ubuntu and Linux systems. How can I find my DNS servers?

[AzkerM]

I'm not sure why the server ends with 1.1 where it should be 127.0.0.1. Well, I might be wrong too. However, for the sake of testing,, can you do sudo nano /etc/resolv.conf and comment the line nameserver 127.0.1.1 starting with #.. also the same time add nameserver 8.8.8.8 then save with CTRL+O and hit enter. Now remember! this is a temporary edit to see whether changing DNS responds to your query. FQDN refers to Fully qualified domain name which is commonly any domain names that not IP addresses.

[AzkerM]

Let us continue this discussion in chat.

[Parthapratim Neog]

Could you, by any chance, have an answer for this?

[AzkerM]

Thanks @A.B. for the edit.. I was wondering how the hell did I miss that :D