Internet not working without preferred DNS server - dns

My machine is connected to the office net work using wifi. My internet was working for some time without any issue. Suddenly this morning the internet stopped working although I could ping to 8.8.8.8 and other network IPs. I set the preferred DNS server and the alternate DNS server and made it work again. My question is why was it working without these settings and why did I need to enter these settings suddenly? What changes did my computer go through without me doing anything?

Had the DNS on your machine been set before? If so,minor changes to a WIFI policy would then make your machine create a second WIFI network connection. This would then make your previously set DNS no longer valid.

Related

Get WSL2 DNS to use Hosts DNS from DHCP

I'm trying to use WSL2 but the DNS isn't working, nothing resolves. I've seen lots of articles about disabling resolv.conf generation and putting in a manual entry, however this won't work for me. My workplace block the port DNS uses so I can't use 1.1.1.1 etc and I can't use the corporate DNS server IP as I want a solution that will work when I go home as well.
Is there a way for WSL2 to be able to use the DNS settings provided by the Hosts DHCP lease? I've tried to change the virtual switch (WSL) in the Virtual Switch Manager to be External but it's still picking up an IP from the DHCP server.
Am I missing some Windows configuration or do I need some Linux Fu to change the config. I was trying to get Podman-Desktop running and couldn't pull any images at work which is what started this off.

how to link local IP Address to a domain name in local network, so website can be accessible to any device using the domain name?

I am a NOOB to programming and networking so please forgive me for any mistakes.
I have searched on stack,google for my problem but the solutions
i found didn't went well with me and so please do consider answering my question
even if you consider it is simple or duplicate question.
My Problem - I have a nodeJS server built using express and it can be accessed on
address http://192.168.209.239:8001/ now i want to access server using domain names like normal website say i want to access the server using http://myserver.app/
found Solutions - i found about DNS but i was not able to set it up, then i found that editing the etc/host file can solve this but domain name was only working on my laptop where the app is running, if i connect my phone to same network* and when i type the domain name it does not work.
I found about mDNS. but i was a very old post which told we can use Apple Bonjour but it is not working as i learned that Microsoft has done some implementation of mDNS
so make Bonjour work disable mDNS in registry and i am not willing to do that.
What i ask - please give me step by step guide how to stepup DNS or mDNS on my machine
so if any device connects to my network it can access the NodeJS app thought its browser using domain URL http://myserver.app/
I am using
nodeJS#16.13.2,
express#4.17.2,
Windows 11 version 21H2 build 22000.376
My Network is like I have connected my mobile hotspot to laptop
and any new device to connected to hotspot so may my mobile is kind of a wifi router.
if a different laptop connects to my hotspot i should be able to access the website using the domain name. myserver.app
My Phone is using Android 11
and please do consider
I do not want to use any online DNS providers like easyDns or AWS
i want a local solution which i can run on my laptop
Ideally you need to DNS server for this : but its wont work with dynamic IP as your machine ip can change after reboot
You can add domain as host entry on each machine : this will not work with mobile and also need to change ip as your machine / server ip change
If you have static ip , just go for any dns service provider easydns , aws and as its inetrnall ip will work for all devices which are in network
Found This may work for y https://www.noip.com/support/knowledgebase/how-to-configure-ddns-in-router/
Starting with Android 9 Pie it is possible to change DNS globally, provided they support TLS. Just go in
Settings → Network & internet → Advanced → Private DNS

How can I connect to an IIS site being served on my computer from my iPad?

Both devices are connected to the same WiFi network.
I have set IIS bindings to allow connections to my IP:
However, my computer's IP address is the same as my iPad's.
Is there a way to make this work?
That's not your IP. Every time you use a laptop on a Wifi network, you'll be using the public IP address of whatever network you're on.
The IP address of "your" computer doesn't belong to your computer. It belongs to the network you're connected to. Your computer is just borrowing it for a while.
Try to set a static IP address for your computer and use another machine to send ping command to it. Then use iPad to connect.
Initially when I posted this question, I was using an xfinitywifi hotspot and I assume that came with a whole host of problems. Full-disclosure, I did not figure out how to make it work in this scenario.
However when I moved to my own home wifi network, I was still having this problem.
I had to do two things, one of which, I know is not recommended, but it was really easy.
First, I had to enter my network and sharing center and set my connection as home connection instead of public which is what I previously had it at.
Second, which is not recommended, I turned off Windows firewall. I only do this when I need to access my site from another device for debugging. I turn it back on when I am done. For a more permanent setup I know it is recommended to just enable the port you need, but I could not figure this out.

Issues SSHing to Raspberry Pi From External IP

I've been trying to SSH to my RPi from an external network for a while with little luck. I've followed all the guides and they say all the same things: get SSH set up, port forward on port 22, and then connect using your external IP address. I've been able to easily SSH to the RPi using my internal IP from the same network with no problem, but not from my external IP. This is my configuration for port forwarding:
That is the internal IP for my RPi's ethernet connection. I've tried it with the IP for WiFi as well and it just has the same effect. When I try to SSH using my external IP, it just times out no matter which internal IP is port forwarded (ethernet or WiFi). I've tried it both on PuTTY on my PC and from my Macbook using
sudo ssh pi#my.external.ip.address
It still just times out. The only thing I can think that might be happening is some issue with a firewall, but I have no idea how firewalls work so if this has been seen before and it is a firewall issue, more detailed guide would be nice.
Even if the issue is not known, is there any way to debug the SSH call and see where exactly it's failing when I use the external IP? Any kind of help is greatly appreciated.
I recently struggled through a lot of this with my pi. As alvits suggests, if you are trying to connect to the pi via the LAN it probably won't work. You need to test from an external IP address.
You shouldn't need to sudo either.
If you are still using pi/raspberry as the username and password, change ASAP. Once the firewall is open it won't take long before you start to see bots trying to log in. I think it was about 30 minutes on my machine. It was interesting for a few days, then annoying. Almost all attacks stopped when I moved off of port 22.
According to this page, it does not appear that my router supports SSH. I was able to find guides online of how to enable it using custom firmware, however I probably won't be attempting that. Thanks for the help anyways!

andlinux slirp network failed

I have installed andlinux Beta 2 on my WinXP. Everything works fine until last night, I don't recall that I ever changed anything on network configuration or andlinux setup, the network stop working inside andlinux. With that said, I mean open a KDE console, I do "ping yahoo.com", I see DNS is resolved correctly, however, no response at all.
My andlinux is startup as a WinXP service. Open windows task manager I can see following services are up and running:colinux-daemon.exe colinux-net-daemon.exe colinux-slirp-net-daemon.exe
On andlinux side, there are two network interface eth0 and eth1. eth1 is configured to communicate with local WinXP. I configured it to use samba to access windows directories, no problem. From WinXP side, I can use ssh to login into andlinux box via eth1 IP address.
eth0 is configured as slirp, no port forwarding. eth0 has IP=10.0.2.15, default gateway is 10.0.2.2, netmask=255.255.255.0; These are configured in /etc/network/interfaces. DNS is 10.0.2.3, which as I just mentioned resolve yahoo.com correctly.
On the windows side, internet works fine. I disabled firewall on all network interface. I rebooted my laptop, no luck. I searched over inet, seem no one has this problem. People say network is done if they kill the colinux-slirp-net-daemon. What frustrated me is that this whole thing worked well, but for no reason it's broken all the sudden. Anyone has experience on this issue, please help, appreciate!
I thought I had the same problem, but then found my andLinux system's network connectivity was actually working fine, and that several things made it difficult to tell what was going on.
Test I did to validate connectivity: wget www.yahoo.com
Behavior I observed that made troubleshooting difficult:
Pings from andLinux - not all hosts will respond to pings from the andLinux OS (ie Ubuntu, not the Host Windows OS). According to my packet captures the pings appear as UDP pings instead of ICMP pings once they leave the host OS's adapter. The major IPs/hosts (like yahoo, google, 4.2.2.2 etc.) on the internet I usually ping to test connectivity currently don't respond to these type of pings.
Traceroutes from andLinux - even when successful, these never show more than 2 hops when done from the andLinux OS. If successful, both hops show 10.0.2.2. If unsuccessful, the second hop just times out. Not sure why, I'm sure there is an explanation.
Packet captures - at the host OS level, the capture (eg wireshark) must be done on the physical interface the traffic is going over. I was initially capturing on the TAP-Win32 Adapter but this only showed X Window traffic.
Installed apt sources URLs no longer valid - Ubuntu 9.04 is long out of support by now, so the URLs in the apt sources.list file didn't exist anymore. This is what got me thrown off in the first place, because I didn't troubleshoot this specifically and just tried to test my internet connectivity first, then got confused by the ping and traceroute behavior seen above. Changed http://us.archive.ubuntu.com/ubuntu to http://old-releases.ubuntu.com/ubuntu/ in sources.list and was good to go.

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