unable to connect to proxmox (but still able to connect to containers)

[marianh]

Hi,

I'm new here, new to Proxmox and fairly new to networking, so excuse basic questions, pls....
I've installed Proxmox as the replacement for my ages old Windows server. I currently run it in test phase, no production use.

I encountered an error (two times) of not being able to reach proxmox host while VMs are still reachable.
I do not know how to investigate (because my lack of experience). Each time reboot of host helped.
First time the error happened overnight, with no user activity.

My setup:
- WRT router (IP 192.168.1.1)
- proxmox on old Dell server HW, with 2 NICs, using just one, IP 192.168.1.10 (set as static in router)
- several Linux containers with IPs 192.168.1.11 and more
- bridged networking

auto lo
iface lo inet loopback

iface eno1 inet manual
iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address  192.168.1.10
        netmask  255.255.255.0
        gateway  192.168.1.1
        bridge_ports eno1
        bridge_stp off
        bridge_fd 0

When it fails, I can ssh/http to guests but I can't ssh/http to proxmox host.
What should I check? If it's cabling, I would not see guests either...

Thnks!

 

[Richard]

I encountered an error (two times) of not being able to reach proxmox host while VMs are still reachable.
I do not know how to investigate (because my lack of experience). Each time reboot of host helped.
First time the error happened overnight, with no user activity.

My setup:
- WRT router (IP 192.168.1.1)
- proxmox on old Dell server HW, with 2 NICs, using just one, IP 192.168.1.10 (set as static in router)
- several Linux containers with IPs 192.168.1.11 and more
- bridged networking

auto lo
iface lo inet loopback

iface eno1 inet manual
iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address  192.168.1.10
        netmask  255.255.255.0
        gateway  192.168.1.1
        bridge_ports eno1
        bridge_stp off
        bridge_fd 0

When it fails, I can ssh/http to guests but I can't ssh/http to proxmox host.
What should I check? If it's cabling, I would not see guests either...

Configuration looks fine. Maybe something wrong in the router setting - but that's pure speculation.


You have probably still access to console? If not connect to a container and back to the host ....


In the host investigate the IP packet flow by tcpdump, e.g.

tcpdump -e -n -i eno1

 

[marianh]

Well, it was not a proxmox problem.
I installed Proxmox on old Dell PowerEdge 2900 I took from our company and by coincidence I used the same IP as we used in the company for the management interface Dell BIOS has (or whatever it is called).
So duplicate IP on the network... once Proxmox was rebooted, it went wrong.
I realized it when during the reboot I could still ping that address...

Stupid, I know

 

[jim.bond.9862]

not that stupid

I have 4 DELL servers here and I always get confused with IP for server and iDRAC interface.