[SOLVED] VM on different hosts no communicate properly

[sja42]

Hello all

I'm a newbie at Proxmox. I've set a Proxmox cluster v8.4.1 with 2 nodes.
I've deployed a VXLAN zone with it's associate VNet (vmnet01).

On each node I have 2 VMs using the vmnet01, they all have internal IP (10.10.30.0) :

• the 4 VMs ping together
• the 4 VM ping 8.8.8.8 and google.com
• on node 1 the first VM : VM1-1 (10.10.30.11) I have an apache responding on http and https
• on node 1 the second VM : VM1-2 can get the index page from the VM1-1 (wget http://10.10.30.11/)
• on node 2 the VM2-1 can't get the index page

In the console I see the log : "Connection to 10.10.30.11:443... connected" but the request never end. However with a nmap I see the ports 80 and 443 are opened, and in the apache logs, I see a trace of the connection from VM2-1 IP

The firewall is disabled on the datacenter and the nodes.
What is missing in my config . I'm really lose with that problem.

thanks !

 

[dherzig]

Hi sja42,

do you have any http->https redirects in your apache config?
Is apache configured to actually serve content over port 443?

From VM1-2 you seem to wget http, but VM 2-1 appears to be connecting to https.

 

[sja42]

Hi dherzig,

Thanks for your reply

yes I have a redirection on my apache, he redirect to 443 properly.

When I'm calling on http from the VM1-2 or VM2-1 I see the redirection : " Location: https://10.10.30.11/ [following]".
And when I'm calling on https, from VM1-2 everithing is ok ; from VM2-1 I don't obtain the response.

So I don't thing the apache conf is in cause, it seems that the call can't come back to the VM2-1.

 

[sja42]

Finally I've found the solution of my problem : I'd missed to set a value of 1450 for the MTU on the Network Device of my VMs.
Now it works fine.

 

[dherzig]

Perfect, happy to hear you found the solution!

Please consider setting the thread to 'solved', this might help people in a similar situation to quicker find the answer.