Unable to reach ubuntu archives or ping any server on any VM/Container

[Defiance_21]

Hello. still new to proxmox and networking in general. Recently setup a proxmox server with some VM's and containers and the other day I setup an OpenVPN and PiHole container. Today my entire wifi network seemed to stop working, no one in the house including me could access anything on the internet, kept receiving an error about DNS addresses not being found. Upon restarting my router some devices were working fine while others weren't. I then proceeded to restore my router settings from a backup from a few days ago and that seemed to have fixes the issues regarding connectivity.

I then go to check on my proxmox server and now my OpenVPN and PiHole both do not work. My ubuntu web server will get hung up on 'A start job is running for Wait for Network to be configured (XXs / no limit)' for awhile. Both the Ubuntu web server and the containers are unable to ping anything and I am unable to execute apt update / upgrade as I get thrown an error stating that I cannot resolve 'archive./ubuntu.com'. All my Windows virtual machines are unable to connect to the internet either.

Like I said I am very new to proxmox and networking so I don't really know how to go about fixing this, is it possible that the DNS I am using is no longer working? Some sort of gateway issue? Router Settings?

Interfaces file

auto lo
iface lo inet loopback

iface enp30s0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.69/24
        gateway 192.168.1.1
        bridge-ports enp30s0
        bridge-stp off
        bridge-fd 0

Sources.list

deb http://ftp.us.debian.org/debian bullseye main contrib

deb http://ftp.us.debian.org/debian bullseye-updates main contrib

deb http://download.proxmox.com/debian/pve bullseye pve-no-subscription

# security updates
deb http://security.debian.org bullseye-security main contrib

If anything else is needed please let me know and I apologize if I am not being concise as to what is wrong.

 

[Lukas Wagner]

Hello,

could you share with use how the network in your virtual machines is configured (IP, gateway, DNS)? Did you change any settings in your router (e.g. point the DNS to the IP of your PiHole? Did you by any chance enable PiHole's DHCP server?

Thanks,

 

[Defiance_21]

Sure no problem

OpenVPN

DNS Domain: 8.8.8.8
DNS Server: 8.8.4.4
IP: 73.80.119.30
Gateway (Should just be the one of my router right??): 192.168.1.1

PiHole

IP: 192.168.1.232
DNS: 127.0.0.1
Gateway: 192.168.1.1

Yes PiHole is set to point to the Ip of the PiHole, at one point the PiHole was working but now it seems to not be at all.

I honestly can't recall whether I enabled piHole's dhcp server (nor do I know how to check, apologies).

 

[Lukas Wagner]

Thank you for your reply.

I'd say that there is generally some problem with the configuration of your router and/or PiHole. It has been since a few years since I've used PiHole, but in general, a configuration like the following should be adequate for most home networks:

• PiHole has a static IP within your network
• In your router, set the DNS that is handed out to your network clients via DHCP to the IP of PiHole (alternatively, set the DNS settings of all relevant network clients manually)
• In PiHole, set the upstream DNS server to one of the available public options (8.8.8.8, 1.1.1.1, etc.)

Some troubleshooting steps to diagnose the problem:

• Check the network settings of your affected clients. They should have an IP in your network, the gateway set to your router's IP address and the DNS set to the address of your PiHole (or some public DNS, if you simply want to have a functioning network again, without using PiHole for now)
• Test if PiHole has proper network connectivity, check it's network settings again in case there are problems.
• Disable the OpenVPN VM for now, to make sure to isolate the problem

Hope this helps.

 

[Defiance_21]

Thank you for your reply.

I'd say that there is generally some problem with the configuration of your router and/or PiHole. It has been since a few years since I've used PiHole, but in general, a configuration like the following should be adequate for most home networks:

• PiHole has a static IP within your network
• In your router, set the DNS that is handed out to your network clients via DHCP to the IP of PiHole (alternatively, set the DNS settings of all relevant network clients manually)
• In PiHole, set the upstream DNS server to one of the available public options (8.8.8.8, 1.1.1.1, etc.)

Some troubleshooting steps to diagnose the problem:

• Check the network settings of your affected clients. They should have an IP in your network, the gateway set to your router's IP address and the DNS set to the address of your PiHole (or some public DNS, if you simply want to have a functioning network again, without using PiHole for now)
• Test if PiHole has proper network connectivity, check it's network settings again in case there are problems.
• Disable the OpenVPN VM for now, to make sure to isolate the problem

Hope this helps.

Currenlty I am just trying to get any VM to work without PiHole at the moment as none of them can get any form of internet connectivity. I tried creating a WebServer from scratch and I am receiving the same exact error meaning that there is likely some setting that got messed with when I rolled back the routers settings.

What settings should I be looking for in my router? I am using a verizon g1100 router if that helps you at all.

P.S sorry for the late reply, I work full time and have been busy with a lot of other things

 

[Lukas Wagner]

Hi,

how is the network for your VMs configured, is it DHCP or static IP assignment? Can you ping IP addresses from your VMs? e.g. ping 1.1.1.1

What are the outputs for ip addr and ip route show for your Ubuntu VM? What name servers are configured in /etc/resolv.conf?

What settings should I be looking for in my router? I am using a verizon g1100 router if that helps you at all.

I am not familiar with this router. Without knowing which settings you changed it's hard to give any advice here, but I'd make sure that your router's DHCP server is enabled. If there is any way to configure the DNS settings that distributed to your network clients via DHCP, make sure that they point to some working DNS (e.g. 1.1.1.1, 8.8.8.8 or your ISP's DNS server).
Maybe consider a factory reset of the router if you cannot find what's wrong.

 

[Defiance_21]

Hi,

how is the network for your VMs configured, is it DHCP or static IP assignment? Can you ping IP addresses from your VMs? e.g. ping 1.1.1.1

What are the outputs for ip addr and ip route show for your Ubuntu VM? What name servers are configured in /etc/resolv.conf?


I am not familiar with this router. Without knowing which settings you changed it's hard to give any advice here, but I'd make sure that your router's DHCP server is enabled. If there is any way to configure the DNS settings that distributed to your network clients via DHCP, make sure that they point to some working DNS (e.g. 1.1.1.1, 8.8.8.8 or your ISP's DNS server).
Maybe consider a factory reset of the router if you cannot find what's wrong.

For the most part everything is set as static, with the PiHole being the only container in the entire node set to DHCP.

I am unable to ping anything with any VM or container, just get thrown a Network Unreachable.


Ip addr Output

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
        valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
        valid_lft forever preferred_lft forever
2: ens18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether f2:d3:ce:01:c5:55 brd ff:ff:ff:ff:ff:ff
    altname enp0s18

ip route show gives me no output at all


The only nameserver I have in

/etc/resolv.conf

is 8.8.8.8

Unless I am missing something I can only add Ip's that are known by my router's DNS and I am unable to control where they point to.... odd.

At this point I am considering a factory reset.

 

[Defiance_21]

Update: Tried factory resetting the router but to no luck. Seems like the issue might be related to how my server is configured. Any help would be appreciated.

 

[Lukas Wagner]

Update: Tried factory resetting the router but to no luck. Seems like the issue might be related to how my server is configured. Any help would be appreciated.

Does the problem still occur when *only* the server (by which you mean, I assume, the Proxmox VE host) is running, with all VMs and containers stopped?

 

[Defiance_21]

Does the problem still occur when *only* the server (by which you mean, I assume, the Proxmox VE host) is running, with all VMs and containers stopped?

So basically what is happening right now is that the vms and containers running on the VE host are suddenly unable to connect to the internet. Due to this both my openVPN and PiHole containers do not work as well.

Every other device outside of my VE host work perfectly fine and have no issues connecting to the internet.

 

[Lukas Wagner]

Okay, my apologies, I thought there still were connectivity issues with other devices in the network.

Could you provide me with the container configuration for your OpenVPN and PiHole containers? You can find them on the PVE host in
/etc/pve/lxc/<id>.conf. Replace <id> with the IDs of your containers.

 

[Defiance_21]

Sure no problem

OpenVPN

arch: amd64
cores: 1
hostname: VPN
memory: 512
nameserver: 8.8.4.4
net0: name=eth0,bridge=vmbr0,firewall=1,hwaddr=B2:53:DE:2B:CC:7C,ip=dhcp,ip6=dhcp,type=veth
onboot: 1
ostype: ubuntu
parent: Working_Basic_Firewall
rootfs: local-lvm:vm-104-disk-0,size=8G
searchdomain: 8.8.8.8
swap: 512
lxc.cgroup.devices.allow: c 10:200 rwm
lxc.mount.entry: /dev/net dev/net none bind,create=dir
lxc.mount.entry: /dev/net/tun dev/net/tun none bind,create=file
lxc.cgroup2.devices.allow: c 10:200 rwm

[Working_Basic_Firewall]
arch: amd64
cores: 1
hostname: VPN
memory: 512
net0: name=eth0,bridge=vmbr0,firewall=1,hwaddr=B2:53:DE:2B:CC:7C,ip=dhcp,ip6=dhcp,type=veth
onboot: 1
ostype: ubuntu
rootfs: local-lvm:vm-104-disk-0,size=8G
snaptime: 1670881093
swap: 512
lxc.cgroup.devices.allow: c 10:200 rwm
lxc.mount.entry: /dev/net dev/net none bind,create=dir
lxc.mount.entry: /dev/net/tun dev/net/tun none bind,create=file
lxc.cgroup2.devices.allow: c 10:200 rwm

PiHole

arch: amd64
cores: 1
features: nesting=1
hostname: PiHole
memory: 512
net0: name=eth0,bridge=vmbr0,firewall=1,hwaddr=AE:E2:42:59:09:52,ip=dhcp,ip6=dhcp,type=veth
onboot: 1
ostype: ubuntu
rootfs: local-lvm:vm-106-disk-0,size=8G
swap: 512
unprivileged: 1

 

[Lukas Wagner]

Okay, some observations:

• searchdomain should not be an IP address. This is the domain name used by if you are trying to resolve a host name that is not a FQDN. For example: If you try to ping foo and searchdomain: example.com, then ping foo.example.com will be tried.
• For any kind of infrastructure, I'd set any ip addresses manually. For your containers, you used DHCP for automatic address assignment. In case of PiHole, static IPs are required because every client needs to have its DNS set to the IP of your PiHole container. If you use DHCP, the address might change and DNS name resolution stops working.
  You can use the PVE GUI to set the IP of your containers. Use some unused IP from your network range, and set the gateway to the IP of your router
• You pass through /dev/net /dev/net/tun - I have no experience with this, but I assume this enables the VPN container to create a TUN device on the host. I'm not sure what possible side effects could occur from this. Consider not staring the VPN container for now and try making the PiHole container work first.

 

[Defiance_21]

Okay, some observations:

• searchdomain should not be an IP address. This is the domain name used by if you are trying to resolve a host name that is not a FQDN. For example: If you try to ping foo and searchdomain: example.com, then ping foo.example.com will be tried.
• For any kind of infrastructure, I'd set any ip addresses manually. For your containers, you used DHCP for automatic address assignment. In case of PiHole, static IPs are required because every client needs to have its DNS set to the IP of your PiHole container. If you use DHCP, the address might change and DNS name resolution stops working.
  You can use the PVE GUI to set the IP of your containers. Use some unused IP from your network range, and set the gateway to the IP of your router
• You pass through /dev/net /dev/net/tun - I have no experience with this, but I assume this enables the VPN container to create a TUN device on the host. I'm not sure what possible side effects could occur from this. Consider not staring the VPN container for now and try making the PiHole container work first.

Alright thank you, I'll see what i can do to get up my PiHole and VPN again. Any idea as to why none of my vm's are able to have an internet connection anymore? All current ones and new ones are suddenly unable to connect to the internet.