[RESOLVED]No internet on ubuntu when disable dhcp

Farisse

@johnpoz said in No internet on ubuntu when disable dhcp:

from your directed query to 192.168.1.1 you resolved google - so set your ubuntu to use that for its dns when you run static.

What do you mean with this ? I thought i already configures my ubuntu for using a dns ?

johnpoz

Well clearly not using that now is it..

When you directed to do dns it work @192.168.1.1

When you just do dig, its saying it can not talk to dns.

when you look with networkctrl status - does it show you dns.. NO... And its not working, so clearly its NOT SET!! if it was, then it would be using it and working...

what does nslookup show you?

user@NewUC:~$ nslookup www.google.com
Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   www.google.com
Address: 172.217.4.196
Name:   www.google.com
Address: 2607:f8b0:4009:806::2004

Here
https://linuxize.com/post/how-to-configure-static-ip-address-on-ubuntu-18-04/

Farisse

Yeah you’re right it should work if it was set do not understand why it doesn’t.

Btw thank you for the link but I can’t process as it is explained. I removed netplan to use the old network configuration ( using /etc/network/interfaces & the screenshot above for the dns)

This is the result of the requested command

alt text

johnpoz

So from your nslookup its working, but its pointing to dnsmasq most likely running locally.. Which in turn forwards to whatever dns you want say 192.168.1.1

So now it should be working?

Farisse

Ubuntu is insane haha >.< You set up everything to be used 'externally' and it choose to use local dnsmasq. Whatever ...

It is working indeed, i'm just afraid to restart the machine and lose the connection again. i prefered to follow what you said to check everything and if its not working anymore search from where it doesn't work. So i'm going to restart now and hope it will still work.

Farisse

as i thought after a restart of the machine. No connectivity anymore.

johnpoz

dude if you can not ping 192.168.1.1 then no you can not do anything...

which has ZERO to do with dhcp, and really zero to do with pfsense at all.. You have other devices on this 192.168.1/24 network... I suggest you head on over to ubuntu forums in your native language to get help on how to setup it up with static..

Farisse

Ok, Well thank you for your help. I already tried in my native language on ubuntu forum, but i got no answer. Whatever, i'll search after how to make it work.

Thank you for your explanations, help & time !

johnpoz

Here is 1st thing you have to test when doing any basic networking troubleshooting.

Can you actually talk to your gateway.. Can you talk to other devices on that network?

If you can not, look in your arp table - you can not talk to ip address xyz, if you can not arp for it..

DHCP has zero to do with actually connectivity - other than handing the client an IP, gateway and dns.. If your doing it static dhcp being on or off on the firewall has nothing to do with connectivity.

If you say it works via dhcp, but not when static - then your not setting up the static correctly... The only way dhcp could have anything to do with your problem is if you were setting up static arp on pfsense. With a reservation that mac address xyz gets 1.2.3.4.. And now when not using dhcp you setup 1.2.3.5 so your static arp does not match up.. So you can not talk to pfsense would = broken connectivity.. Simple test of ping and knowing if you setup static arp or not would be key here..

Farisse

Thank you for your help, i never heard about it, i was usually using ping and traceroute command. i am not a specialist. I maybe gave a wrong explanation, but as you said it's not about pfsense son i should ask to ubuntu users. My question was about why it was working when the dhcp on pfsense was enabled and static ip on ubuntu, but not with dhcp was disabled and static ip on ubuntu. For sure it's something about the dns I hoped to find an answer here because i thought i has something to do with the dhcp server but it's not...
I'll try other linux/ubuntu forums or just switch to another operating system.

Many thanks for your help man ! I appreciate it, you made me understand things I understood/learned wrong.
Big up ;-)