DNS Issues - Cannot connect to internet without VPN(warp)

[Ut M]

I am just getting DNS errors all the time now. It used to happen weekly once or twice, but now I can't use internet without VPN(cloudfare warp here)
I can access the sites via Ip addresses and can successfuly ping them. Since Warp doesn't work with my ftth on iPhone, I can't even use the connection with my mobile.
I tried several different DNS'es including OpenDns, Google's dns, 1.1.1.1(cloudfare's work with warp idk why.) .
Never had this issue with ADSL connection we previously had. 😕 Where could be the issue? any possible fixes? I tried with DHCP disabled and manually setting ipv4 and dns which didn't work either.

 

[JB701]

I think bsnl might be messing with unencrypted dns traffic.

Warp uses encrypted dns. You can set warp in encrypted dns only mode without VPN see if that works.

Are pings to 8.8.8.8 timing out? If thats the case there is a routing issue likely.

For ios use encrypted dns like this

How to Enable Encrypted DNS on iPhone iOS 14

Protect your online privacy: find out how to enable encrypted DNS on iPhone 14.0. Also, we look at what DNS is and why it matters for privacy.

rodneylab.com

 

[Oppili]

Reduce MTU and see if it works

 

[Lolita_Magnum]

Kindly check in Command Prompt if,
nslookup broadbandforum.co

Returns an IP address.
While you are at it, for now also check, if enabling Secure DNS(select service from dropdown) in your browser allows you to have web access.
Simplest thing would also be to reboot the router see it fixes.
Did you recently made any changes to your router?

 

[Ut M]

@Oppili Actually, I tried to reduce MTU and set it to 1460 from 1492 yesterday by trying out sending packets of different sizes but it didn't help.

@Lolita_Magnum
here are the results with warp enabled.

With warp disabled.

I haven't changed any settings in past few weeks, this dns issue is happening since the beginning(switched to ftth in oct-nov 2020) but now facing this issue permanently. Tired of complaining to the ISP, they just don't do anything now.


@JB701 I will try out setting up encrypted dns and give an update.

 

[Oppili]

MTU 1460 can still be higher, try 1430 or lower

 

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[Lolita_Magnum]

If it was an MTU issue then, normal ICMP and VPN wouldn't have worked either. It's clear it isn't.
Last thing you could on your side is, try to reset your router, if you have any extenders or access point or firewall connected to your home network, do a factory reset to that too. If none of that works, it's pretty clear that due to some misconfiguration on your ISPs side, port 53 must be blocked for outbound connection. Just complain to your ISP that you internet doesn't seems to work, don't try to explain anything to him, and warn him that you'd leave if it isn't resolved soon.
If the isp doesn't want to work with you and move on to a different ISP, people like this should not be entertained.
Lastly if you are stuck with bsnl, you'd have to implement secure dns over https or tls.
Warp sometimes routes you to international servers and an added latency while using that doesn't really justifies as a solution.