Network configuration

[Cyrille]

Hello,

I allow myself to add a new demand, to try to find a solution to my problem.
Many topics are similar to mine but I can't find a solution.

Thank you in advance to those who will help me.

I installed Proxmox on a server at home (test lab environment).

Here is its network configuration of Proxmox :

auto lo
iface lo inet loopback

auto enp0s31f6
iface enp0s31f6 inet static
    address 192.168.1.100/24
    gateway 192.168.1.1

auto vmbr1
iface vmbr1 inet static
    address 10.10.10.200/24
    bridge-ports none
    bridge-stp off
    bridge-fd 0
    post-up echo 1 > /proc/sys/net/ipv4/ip_forward
    post-up iptables -t nat -A POSTROUTING -s '10.10.10.0/24' -o enp0s31f6 -j MASQUERADE
    post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o enp0s31f6 -j MASQUERADE

Here is its network config of my VM :

auto ens18
iface ens18 inet static
    address 10.10.10.201
    netmask 255.255.255.0
    gateway 10.10.10.200
    bridge-ports none
    bridge-stp off
    bridge-fd 0

On my laptop, i'm set on the network with static IP 192.168.1.110 with the gateway 192.168.1.1.

I would like access to my VM on proxmox (10.10.10.201) from my laptop.

I added route :

~# ip route
default via 192.168.1.1 dev enp0s25 proto dhcp metric 100
10.10.10.0/24 via 192.168.1.110 dev enp0s25
192.168.1.0/24 dev enp0s25 proto kernel scope link src 192.168.1.110 metric 100

But can't access to the VM.

Ping the virtual interface works good :

cyrille@homepc:~$ ping 10.10.10.200
PING 10.10.10.200 (10.10.10.200) 56(84) bytes of data.
64 bytes from 10.10.10.200: icmp_seq=1 ttl=64 time=0.761 ms
64 bytes from 10.10.10.200: icmp_seq=2 ttl=64 time=0.889 ms

But can't ping the VM doesn't work :

cyrille@homepc:~$ ping 10.10.10.201
PING 10.10.10.201 (10.10.10.101) 56(84) bytes of data.
From 192.168.1.110 icmp_seq=1 Destination Host Unreachable
From 192.168.1.110 icmp_seq=2 Destination Host Unreachable
From 192.168.1.110 icmp_seq=3 Destination Host Unreachable

Does anyone have an idea where this could be stuck?

If you need more information I am available.

Thanks to you.

 

[Dominic]

Hi,

have you already tried to inspect traffic on the interfaces using something like the following?

tcpdump -envi vmbr1 'icmp'

 

[Cyrille]

Hello,

Thanks to help me.

reading from file icmp.pcap, link-type EN10MB (Ethernet)

09:25:17.027171 IP 192.168.1.110 > 192.168.1.100: ICMP echo request, id 4236, seq 1, length 64
09:25:17.027196 IP 192.168.1.100 > 192.168.1.110: ICMP echo reply, id 4236, seq 1, length 64
09:25:18.036353 IP 192.168.1.110 > 192.168.1.100: ICMP echo request, id 4236, seq 2, length 64
09:25:18.036374 IP 192.168.1.100 > 192.168.1.110: ICMP echo reply, id 4236, seq 2, length 64

09:25:28.595854 IP 192.168.1.110 > 10.10.10.200: ICMP echo request, id 4237, seq 1, length 64
09:25:28.595894 IP 10.10.10.200 > 192.168.1.110: ICMP echo reply, id 4237, seq 1, length 64
09:25:29.620344 IP 192.168.1.110 > 10.10.10.200: ICMP echo request, id 4237, seq 2, length 64
09:25:29.620373 IP 10.10.10.200 > 192.168.1.110: ICMP echo reply, id 4237, seq 2, length 64

When I ping 10.10.10.201 (guest) there is no capture and from laptop : Destination Host Unreachable

 

[Cyrille]

I'm continuing to search, I made a little recap to make it a little clearer.

Do you think that the problem comes from Proxmox? Maybe my router?

All FW disabled.

Thanks in advance.

LAPTOP : enp0s25 (192.168.1.110) :

Ping 192.168.1.110 = OK
Ping 192.168.1.100 = OK
Ping 192.168.1.1 = OK
Ping 10.10.10.200 = OK
Ping 10.10.10.201 = Destination Host Unreachable

Routage table

default via 192.168.1.1 dev enp0s25 proto dhcp metric 100
10.10.10.0/24 via 192.168.1.110 dev enp0s25
10.10.10.201 via 192.168.1.110 dev enp0s25
192.168.1.0/24 dev enp0s25 proto kernel scope link src 192.168.1.110 metric 100

PROXMOX : enp0s31f6 (192.168.1.100)

Ping 192.168.1.110 = OK
Ping 192.168.1.100 = OK
Ping 192.168.1.1 = OK
Ping 10.10.10.200 = OK
Ping 10.10.10.201 = OK

Routage table

default via 192.168.1.1 dev enp0s31f6 onlink
10.10.10.0/24 dev vmbr1 proto kernel scope link src 10.10.10.200
192.168.1.0/24 dev enp0s31f6 proto kernel scope link src 192.168.1.100

VM GUEST DEBIAN : ens18 (10.10.10.201)

Ping 192.168.1.110 = OK
Ping 192.168.1.100 = OK
Ping 192.168.1.1 = OK
Ping 10.10.10.200 = OK
Ping 10.10.10.201 = OK

Routage table

default via 10.10.10.200 dev ens18 onlink
10.10.10.0/24 dev ens18 proto kernel scope link src 10.10.10.201

GATEWAY (the same for PROXMOX and LAPTOP) : 192.168.1.1

VM CARD BRIDGE : VMBR1 (10.10.10.200)

 

[Cyrille]

Hello,

I'm still investigating. : )

I had to reinstall Proxmox (on a new machine) I put the same configuration and the problem is exactly the same.

I changed my router, to create a new network totally independent but still the same thing.

From several client machines the problem remains the same.

-----------------------------------------

On the other hand when I stay on the same network (Proxmox and bridge) no problem.

Small schematic summary :

Network 192.168.1.1/24 with Bridge interface 192.168.1.200 - (VM .201)

Proxmox ->   Ping 192.168.1.200  = OK
Proxmox ->   Ping 192.168.1.201  = OK
Laptop  ->   Ping 192.168.1.200  = OK
Laptop  ->   Ping 192.168.1.201  = OK

Network = 192.168.1.1/24 with Bridge interface 10.10.10.200- (VM .201)

Proxmox ->   Ping 10.10.10.200  = OK
Proxmox ->   Ping 10.10.10.201  = OK
Laptop  ->   Ping 10.10.10.200  = OK
Laptop  ->   Ping 10.10.10.201  = Unreachable

I will now use packet tracer to make new tests. : )