Turning off DNS Caching

[Lantis]

https://www.youtube.com/watch?v=_NqHpRHl8gQ

Make sure you use SSH not Telnet if you’re on 1.10 or later.

[RomanHK]

Failsafe mode, then remove those two options. Reboot and see if it’s ok. Otherwise a full failsafe reset.
It won’t be a brick.

These choices work for me, he probably put it in the wrong place.

[RomanHK]

Failsafe mode, then remove those two options. Reboot and see if it’s ok. Otherwise a full failsafe reset.
It won’t be a brick.

Ok, so can you provide a link about how to boot into failsafe mode?

When you get into failsafe mode, what you wrote to @Lantis, run the command via PuTTY:

Code: Select all

mtd -r erase rootfs_data

[Lantis]

Why erase everything if only two lines caused a problem? It is worth trying to get those first

[RomanHK]

Why erase everything if only two lines caused a problem? It is worth trying to get those first

I guess these two lines can't be the case - it's a dhcp v4 file and shouldn't have the catastrophic effect that the router won't boot.

EDIT: And if the router normally boot up, wouldn't it be enough to set up a static IP on the PC and fix the lines?

But good, let's try to erase the two lines first.

[pmerrill]

Ok, got into failsafe mode ok. Changed the two lines back to the way they were, powered off the router, powered it back on and works fine now.

The changes I made were in the /etc/config/dhcp file in the dnsmasq section.

It's an Archer C7 V2 if that helps but it was those 2 lines that caused the problem.

[Lantis]

No idea, not my area of expertise and I’ve never looked into it. But it must now be comforting to know that you can recover your router if it goes wrong again

[RomanHK]

This is really weird, it should work: https://oldwiki.archive.openwrt.org/doc/uci/dhcp

This option is included in OpenWrt LuCI:



Nothing, everyone can be wrong, so sorry .

[pmerrill]

This is really weird, it should work: https://oldwiki.archive.openwrt.org/doc/uci/dhcp

This option is included in OpenWrt LuCI:



Nothing, everyone can be wrong, so sorry .

Not to worry, no harm done. What was curious was that with the changes the router booted fine, all the lights were flashing like it was working but no way could I connect and there was no access to the internet either.

I'll keep doing some research and see if I can sort it out.

[pmerrill]

So this is getting very strange now and given my personality, I ain't giving up! So here's the curious thing, if I login to the router and do nslookup twitch.tv I can see it return 195.46.39.1, which is a block page from safedns.

If I go to my PC and I do nslookup twitch.tv from cmd, then I get
> nslookup twitch.tv
Server: Gargoyle.lan
Address: 192.168.1.1

Non-authoritative answer:
Name: twitch.tv
Addresses: 151.101.130.167
151.101.66.167
151.101.194.167
151.101.2.167

So then I went back to the router and executed
# killall -1 dnsmasq

which I understand will clear the router DNS cache

I then did a lookup of twitch.tv again and it came back with the same 195.46.39.1 and yet nslookup twitch.tv from my PC (via cmd window) still returns 151.101.66.167. Yet, if I enter twitch.tv from my google browser on my phone connected to wifi, it comes back with "This site can't be reached".

Ideas???