Newbie out of their depth - Router changed, can ping Proxmox Host but not access the webGUI

AnyNameYouWish

New Member
May 9, 2023
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Hello!

I had a succesful enough Proxmox Environment (thanks to Learn Linux TV!) for a couple of months.

And then I changed my router.

The old router was allocating IPs in the range of 192.168.0.1-255, and all was well. Proxmox host had an IP of 192.168.0.206
The new router started allocated IPs in the range of 192.168.50.1-255, and proxmox was refusing to connect (I have already forgotten what the IP I was trying here), but I did some reading up and understood that the ProxMox server was probably wanting to be allocated its original static IP of 192.168.0.206.

So I changed the router to be in, and set IPs, within 192.168.0.1 (2-255).

I have multiple devices in 192.168.0.xx and the ProxMox host in 192.168.0.206.
I enter precisely https://192.168.0.206:8006/ and no web browser can connect.
However, I can mutually ping the ProxMox host and any of the devices in 192.168.0.xx

And a bonus laugh for you if you got this far - while reading this I had a brainwave and thought "Oh I should change the *router's* subnet mask!"
So I changed it to 255.255.255.255 (mixing up precision, I think I wanted to try 255.255.0.0) and suddenly nothing could access the internet and I had to factory reset the router. :facepalm:

What am I missing? How can I pick up the slack in what I don't yet understand?
Thanks in advance, you smart and beautiful people!

edit - The router is an Asus TUF Gaming AX4200.
 
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If you feel like 192.168.50.* is different from 192.168.0.* then the subnet mask should be 255.255.255.0 (they only differ where the bits are 0).
What are the outputs of ip a and cat /etc/network/interfaces on your Proxmox host (using a physical keyboard and display)?
 
  • ip a generates 3 listings, the relevant one looks like
    • vmbr0: <Broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
    • link/ether 34:17:eb:ce:31:02 br ff:ff:ff:ff:ff:ff:ff
    • inet 192.168.0.206/24 scope global vmbr0
      • valid_lft forever preferref_lft forever
    • (Then it does an inet6 that I've omitted for brevity)
  • cat etc/network/interfaces generates
    • auto lo
      • iface lo inet loopback
    • iface eno1 inet manual
    • auto vmbr0
    • iface vmbr0 inet static
    • address 192.168.0.206/24
    • gateway 192.168.0.1
    • bridge-ports eno1
    • bridge-stp off
    • bridge-fd 0

ohhhh is it the /24 that's throwing it?
edit: oh, no, /24 is right for a 255.255.255.0 mask.

edit2: transcribed by hand so please query any typos. Probably my error rather than something surprising.
 
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  • ip a generates 3 listings, the relevant one looks like
    • vmbr0: <Broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
    • link/ether 34:17:eb:ce:31:02 br ff:ff:ff:ff:ff:ff:ff
    • inet 192.168.0.206/24 scope global vmbr0
      • valid_lft forever preferref_lft forever
    • (Then it does an inet6 that I've omitted for brevity)
  • cat etc/network/interfaces generates
    • auto lo
      • iface lo inet loopback
    • iface eno1 inet manual
    • auto vmbr0
    • iface vmbr0 inet static
    • address 192.168.0.206/24
    • gateway 192.168.0.1
    • bridge-ports eno1
    • bridge-stp off
    • bridge-fd 0

ohhhh is it the /24 that's throwing it?
edit: oh, no, /24 is right for a 255.255.255.0 mask.

edit2: transcribed by hand so please query any typos. Probably my error rather than something surprising.
It looks fine. Is the IP address of your router 192.168.0.1? Is 192.168.0.206 outside of the DHCP range? I think the problem is on the router (or firewall) side of things.
 
Yes, IP address of the router is 192.168.0.1. I set this about 45 minutes ago, prior to that it was 192.168.50.1 - changed it to 192.168.0.1 to better emulate the old router.


Router says the IP Pool starting range is 192.168.0.2 and ending range is 192.168.0.254 - so 192.168.0.206 should be within that range.

The router is an Asus TUF Gaming AX4200. Bought for the non gaming features tbh! I'll add that to the OP too.

Edit: Out of curiosity I tried hosting a calibre server on :8080 on a random Windows host in the same subnet, was able to connect perfectly fine to that server through http on a device that can't hit the ProxMox host.
 
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Tried shuffling deckchairs on the titanic ethernet ports on the router and still no change.
IP is presented, IP box thinks it has matches IP router assigns it.
Can still ping back and forth, just can't see the webgui.

At this point I am tempted to set the old router back up and quickly back everything up (rookie error not to, yes) and then nuke and start again.

Maybe learn how to use Docker at last.

Anyone got any clues before I fetch the atom splitter?
 
Yes, IP address of the router is 192.168.0.1. I set this about 45 minutes ago, prior to that it was 192.168.50.1 - changed it to 192.168.0.1 to better emulate the old router.

Router says the IP Pool starting range is 192.168.0.2 and ending range is 192.168.0.254 - so 192.168.0.206 should be within that range.
Since you are assigning a static IP to the Proxmox (in /etc/network/interfaces), it should not be in the DHCP range (which will be given to clients that use DHCP). Change the DHCP range of your router and make sure to assign Proxmox an unused IP address. Reboot Proxmox after making the change and show the output of ip a and ip r, please.
EDIT: Or change the Proxmox configuration to DHCP and set a fixed DHCP assignment for Proxmox in the router. It depends on how you want to configure your network.
 
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Since you are assigning a static IP to the Proxmox (in /etc/network/interfaces), it should not be in the DHCP range (which will be given to clients that use DHCP). Change the DHCP range of your router and make sure to assign Proxmox an unused IP address. Reboot Proxmox after making the change and show the output of ip a and ip r, please.
EDIT: Or change the Proxmox configuration to DHCP and set a fixed DHCP assignment for Proxmox in the router. It depends on how you want to configure your network.
Okay I have changed the DHCP range to 2-200 and explicitly told the router to give ProxMox .206 as an address.

I am now having a Real Idiot moment, once I log into the CLI on the ProxMox host itself, anything I type and press enter on, eg. "ip a", is not registered as a command. It just prints it and goes to the next line. This is a separate issue but it means I have no idea whow to give you ip a and ip r even though it was working yesterday. Whoops!


EDIT: APPARENTLY I WAS JUST IMPATIENT, IT JUST RAN EVERYTHING I ASKED IT TO!! HOLD ON..

ip a:
vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 34:17:eb:ce:31:02 brd ff:ff:ff:ff:ff:ff
linet 192.168.0.206/24 scope global vmbr0
valid_lft forever preferred lftforever
then an ivp6 bit again

ip r:
default via 192.168.0.1 dev vmbr0 proto kernel onlink
192.168.0.0/24 dev vmbr0 proto kernel scope link src 192.168.0.206
 
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ip a:
vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 34:17:eb:ce:31:02 brd ff:ff:ff:ff:ff:ff
linet 192.168.0.206/24 scope global vmbr0
valid_lft forever preferred lftforever
then an ivp6 bit again

Is this really the full output? Where is your physical network interface?

Please provide the current full output in code-tags each (or take good readable photos) of:
  • ip a
  • cat /etc/network/interfaces
  • cat /etc/hosts
  • systemctl status pve-cluster
  • systemctl status pveproxy
  • systemctl status pvedaemon
 
Do on windows host :
ping 192.168.0.206
arp -a|findstr 192.168

On proxmox:
curl -sk https://192.168.0.206:8006

You said you can ping, can you ssh from windows to proxmox?


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

Code:
PING from windows host:
    Pinging 192.168.0.206 with 32 bytes of data:
    Reply from 192.168.0.206: bytes=32 time<1ms TTL=64
    Reply from 192.168.0.206: bytes=32 time<1ms TTL=64
    Reply from 192.168.0.206: bytes=32 time<1ms TTL=64
    Reply from 192.168.0.206: bytes=32 time<1ms TTL=64

Code:
 ARP from windows host:

Interface: 192.168.0.55 --- 0x10
  192.168.0.1           c8-7f-54-20-b1-e4     dynamic
  192.168.0.48          80-8a-bd-ac-7e-85     dynamic
  192.168.0.79          1e-b5-f9-3c-de-3a     dynamic
  192.168.0.94          e4-5f-01-fd-58-6c     dynamic
  192.168.0.137         b2-40-57-6b-ba-e0     dynamic
  192.168.0.206         34-17-eb-ce-31-02     dynamic
  192.168.0.255         ff-ff-ff-ff-ff-ff     static

Code:
 Curl -Er, I press enter and nothing seems to happen.

I can SSH! Although it took about 2 minutes between typing in credentials and being "logged in". That seems a long time?
I can copy/paste my outputs much easier now!
 
Is this really the full output? Where is your physical network interface?

Please provide the current full output in code-tags each (or take good readable photos) of:
  • ip a
  • cat /etc/network/interfaces
  • cat /etc/hosts
  • systemctl status pve-cluster
  • systemctl status pveproxy
  • systemctl status pvedaemon
Sorry, I had truncated it due to typing by hand as previous post. Now I've SSH'd in (and had the patience to let it work), I can paste these much more easily now.

Code:
 ip a
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: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
    link/ether 34:17:eb:ce:31:02 brd ff:ff:ff:ff:ff:ff
    altname enp0s25
3: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 34:17:eb:ce:31:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.206/24 scope global vmbr0
       valid_lft forever preferred_lft forever
    inet6 fe80::3617:ebff:fece:3102/64 scope link
       valid_lft forever preferred_lft forever

Code:
cat /etc/network/interfaces
auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.0.206/24
        gateway 192.168.0.1
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0


Code:
 cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
192.168.0.206 pve.home pve

# The following lines are desirable for IPv6 capable hosts

::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts


Code:
root@pve:~# systemctl status pve-cluster

root@pve:~# systemctl status pveproxy

root@pve:~# systemctl status pvedaemon

it sat thinking about these last 3 fellas for about a minute each before I tried the next one. I've left pvedaemon running and if it says anything I'll update this post.

So uhhhhhh.. ProxMox isn't running, huh?
 
I can SSH! Although it took about 2 minutes between typing in credentials and being "logged in". That seems a long time?
Possibly means your DNS is broken in some way, although 2min is too long even for that.
If you have ssh, then you dont need to retype anything manually and shorten things that may seem not relevant to you.
Copy paste the requested information from ssh session and use CODE tags.

reboot your host. Then run : journalctl -b
eyeball the output, if you dont find anything interesting, attach file here.


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
Maybe a silly question, but....did you try and clear cache and history of your webbrowser?
Or try different browsers, like Chrome, Firefox...
 
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Maybe a silly question, but....did you try and clear cache and history of your webbrowser?
Or try different browsers, like Chrome, Firefox...
I appreciate anything, always! Thank you for posting - yeah, tried different browsers, different devices, getting nothing.
And the box has now been sitting at
Code:
reboot

for 15 minutes.

I think the router might be a red herring?
 
I appreciate anything, always! Thank you for posting - yeah, tried different browsers, different devices, getting nothing.
And the box has now been sitting at
Code:
reboot

for 15 minutes.

I think the router might be a red herring?

is this message from a physical monitor or via SSH ?
 
Physical monitor - I've typed 'reboot', pressed enter, and the cursor is just sitting there flashing on the next line.
 
"Tried shuffling deckchairs on the titanic ethernet ports on the router and still no change."

- in my country some ISP routers have dedicated ports for IPTV at the onboard switch.
Maybe you plugged the PVE host in an IPTV port..?
 
Maybe you plugged the PVE host in an IPTV port..?
he can ping and ssh into PVE, his local curl command ran from PVE shell to PVE IP hangs. I'd say the issue is in services, not in network.

As an additional test try:
curl -sk https://127.0.0.1:8006|grep title

If it works, you should see something like:
<title>pve7opt6-1 - Proxmox Virtual Environment</title>

P.S. if it still hasnt rebooted - press the power button


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
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