[SOLVED] Initial Setup - DNS Settings Not Working, Can't Connect Externally

[CashewCaliphate]

First time proxmox user here, so it's hopefully something simple, but I can't connect to anything externally because my DNS settings aren't working.

I have a simple, conventional home network setup. No proxies or VPNs to account for. I confirmed entries in /etc/hosts as well as /etc/hostname. I tried google's public DNS server, as well as the DNS server on my router (which was the default). I'm now at a loss as to why this is so difficult. Current settings are as follows.

Search domain: proxmox.local
DNS Server 1: 8.8.8.8
DNS Server 2: 8.8.7.7

/etc/hosts
127.0.0.1 localhost.localdomain localhost
192.168.1.34 proxmox.leonardo.local proxmox pvelocalhost

/etc/hostname
proxmox

Out of desperation, I also tried setting the "Search domain" field to "proxmox.leonardo.local" as well as "leonardo.local" but neither of those helped either. wget still just returns "unable to resolve host address" for any external domain attempt.

 

[dietmar]

Is the network working, i.e. can you access 8.8.8.8? Test with:

# ping 8.8.8.8

 

[CashewCaliphate]

Running a ping command from the shell doesn't return anything at all, unfortunately. But if wget cannot resolve hosts then I think it stands to reason that networking doesn't work for all of proxmox. I can access and ping external IPs from any other device on my LAN, though.

 

[wbumiller]

Can you ping anything in the LAN? Can you ping the gateway? Is your network up properly? (Check `ip addr` for a correct address on the correct interface and `ip route` for a default route.)
(Oh and I think that 8.8.7.7 should be 8.8.4.4?)

 

[remark]

Please show 'ip addr', 'ip route' and 'traceroute 8.8.8.8' commands output.

 

[CashewCaliphate]

Can you ping anything in the LAN? Can you ping the gateway? Is your network up properly?

As I said in my previous post, any device on my LAN (except proxmox) can externally ping addresses without issue. If I try and ping destinations (internal or external) from a proxmox shell, the command doesn't even return results. The command line disappears and the shell just seems to freeze. (I can't enter any further commands):

 ping 192.168.1.1 (192.168.1.1) 56(84) bytes of data.

(That's the only thing that happens when I try to ping from proxmox shell).

Check `ip addr` for a correct address on the correct interface and `ip route` for a default route.

I'm only using one LAN port on my motherboard (eth0), and proxmox created interface vmbr0 in bridge mode automatically. Here is the output of the two commands you referenced:

Oh and I think that 8.8.7.7 should be 8.8.4.4?

Yeah, you're correct, sorry about that. I actually did already have 8.8.4.4 in the settings though, not sure why I typed 8.8.7.7 here instead.

traceroute 8.8.8.8

just returns

* * * *

for each line on all attempts.

 

[remark]

Maybe your router 192.168.1.1 has any of reject filters that now allow Proxmox to send packets outside. Can you check that?

 

[CashewCaliphate]

Maybe your router 192.168.1.1 has any of reject filters that now allow Proxmox to send packets outside. Can you check that?

I wouldn't know how to check that, truthfully. I'm using Tomato Firmware v1.28 on a Linksys E4200 router. I don't know how/why it would reject packet transmission for one object on the LAN but literally none of the dozens of others on the LAN.

 

[remark]

Another reason of such behavior is that you can have IP address conflict: two identical IP addresses at same network. Please check that too.

 

[remark]

I wouldn't know how to check that, truthfully. I'm using Tomato Firmware v1.28 on a Linksys E4200 router. I don't know how/why it would reject packet transmission for one object on the LAN but literally none of the dozens of others on the LAN.

It is possible and it depends on how your router is tuned.
You can check something like 'Firewall' settings on your router.
It seems that IP address, mask and default gateway settings on your Proxmox are correct, and if you can reach Proxmox by network, then physical network is fine.
Then, we have two options -- your router and IP conflict.
In rare cases, may be MAC address conflict. But I saw this only once in my life.

 

[CashewCaliphate]

Another reason of such behavior is that you can have IP address conflict: two identical IP addresses at same network. Please check that too.

Ah-ha! Okay, this merits some investigation, thank you. While there doesn't appear to be any conflicts in the ARP table of the router, I think perhaps one area to look into further is the IP address of the physical box, versus the IP address of the proxmox node.

When my router detected a machine (prior to proxmox even being installed), I gave it a static IP through the router of 192.168.1.34. Then, when I setup proxmox, I told proxmox to give itself a static IP of 192.168.1.34, thinking that they would be synonymous. On my router's ARP table, there's only one entry for 192.168.1.34, and the host name is the machine name, not the proxmox host name. So that could very well be the issue.

I assume those IP addresses (machine vs proxmox node) would need to be different (which they curren't aren't). I'll play around with it and report back with my findings--thank you!

 

[remark]

What DHCP ip address range is defined in your router?

 

[CashewCaliphate]

IP conflict was definitely the issue, thanks remark!

A simple problem really, if you know what to look for in the first place I changed the IP of the proxmox node to a different address that didn't match the physical machine, and I now have external connectivity using my router's DNS.

Appreciate the assist!

 

[remark]

Well, all the problems resolved so easy
Very glad for that!
Always at your service.
Live long and prosper.

 

[floh]

Hello!

I'am having the same problem.
Tested everything mentioned above but nothing helped.

the only thing I found, that /etc/resolv.conf the nameserver was in an extra isolated network
So I changed the ip address to the dhcp server in the other network which can access the internet.
I'm using VLANS - both configurated with static ip addresses.

I can ping in both networks locally

And my VMs can ping 8.8.8.8
So I think there is only one config file worng.
Maybe because I installed the proxmox out of the isolated network?

Any ideas how to solve this problem?