Proxmox 3.4 --> 4.3 Network problem

Didier Misson

Nov 30, 2016

I have 2 servers at OVH, using Proxmox 3.4 since 2 years.

I move all containers 3.4 from srv01 to srv02
I reinstall srv01 in Proxmox 4.3
... scp, restore...
Ok, the container is up in 4.3.

But network doesn't work. :confused:
I read several posts on this forum, and doc... but not yet working.

srv01 has it own IP address (

From the OVH manager, I move an IP /32 ( on srv01 for this container).
I try to have this container using this IP /32

I don't defined this IP /32 on the Proxmox host :
normal... it will not be a Proxmox interface, but a container interface...

I delete all OLD interfaces (coming from Proxmox 3.4) from the container.

I try to create a new eth0 interface with :

MAC auto (I put nothing)
Bridge vmbr0
Gateway : (same IP)

in the container network interface :
# Auto generated lo interface
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
# --- BEGIN PVE ---
        post-up ip route add dev eth0
        post-up ip route add default via dev eth0
        pre-down ip route del default via dev eth0
        pre-down ip route del dev eth0
# --- END PVE ---

# ifconfig -a
eth0      Link encap:Ethernet  HWaddr de:c2:78:96:f1:85
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::dcc2:78ff:fe96:f185/64 Scope:Link
          RX packets:812 errors:0 dropped:6 overruns:0 frame:0
          TX packets:1705 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:92198 (92.1 KB)  TX bytes:73770 (73.7 KB)

lo        Link encap:Local Loopback
          inet addr:  Mask:
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:8203 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8203 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:859859 (859.8 KB)  TX bytes:859859 (859.8 KB)

# ip route
default via dev eth0 dev eth0  scope link

Doesn't work ...

I see several examples, but seem to use the vmbr0
But here, I have eth0 !

All seem logical, but I miss probably some points...

Thanks ;)

No, I don't create a virtual MAC in the OVH manager,
because I NEVER need before. :cool:

With Proxmox 3.4, I simply move my IP or block IP from one server to the new server, and it's work !
I even don't define IP routes... and it was ok. :)

I yet make this yesterday in 3.4...
If I need to manually create a virtual MAC for each IP one by one for 4.3 ? ...

And before, with 3.4 ?
Of course I understand that OVH, when moving the IP, make a ARP definition in their routers, between the IP and the MAC of the servers
So why it was working before without be obliged to manually defined virtual MAC addresses ?

It can be borrying when you must move, quickly, an range of 16 or 32 IPs addresses... one by one :eek:

But ok, I will try.

I change the gateway, to
Not yot working.

I will test the virtual MAC this evening or tomorrow.

Thanks. :)
Hello Tom

I follow this guide for Proxmox 4.3 and OVH.

I create Virtual Mac via tha OVH manager, and I put this Virtual Mac in the container IP configuration.
All is OK now. :)
Thanks for your help.
Not yet perfect... IPv6 ... ;)

OVH range is
Gateway : 2001:41d0:0002:a1ff:ff:ff:ff:ff

I want to use 65536 IPv6 to container 324

I assign the OVH Virtual Mac to the container.
Ok in IPv4
I assign IPv6 too , on same eth0 :

IPv6/CIDR : 2001:41d0:0002:a1bc:0000:0000:0144:0000/112
Gateway : 2001:41d0:0002:a1ff:ff:ff:ff:ff

Ping6 is ok on this IPv6.
$ ping6 2001:41d0:0002:a1bc::144:0
PING 2001:41d0:0002:a1bc::144:0(2001:41d0:2:a1bc::144:0) 56 data bytes
64 bytes from 2001:41d0:2:a1bc::144:0: icmp_seq=1 ttl=54 time=23.1 ms
64 bytes from 2001:41d0:2:a1bc::144:0: icmp_seq=2 ttl=54 time=23.0 ms

But I define a web site on 2001:41d0:0002:a1bc::144:100
I cannot reach it !
Timeout. :(
Apache2 VirtualHost seem correctly defined for IPv6

$ ping6 2001:41d0:0002:a1bc::144:100
PING 2001:41d0:0002:a1bc::144:100(2001:41d0:2:a1bc::144:100) 56 data bytes
From 2001:41d0::fc2 icmp_seq=1 Destination unreachable: Address unreachable

I test with tcpdump : the container receive the IPv6 packet 2001:41d0:0002:a1bc::144:0
but not the 2001:41d0:0002:a1bc::144:100 :confused:

Why ?
It's inside de range
IPv6/CIDR : 2001:41d0:0002:a1bc::144:0/16

Probably I don't yet understand IPv6 ... :cool:

Hi I have got a similar problem.
I link a IP bloc with a Vrack and than can't create virtual mac for this adresses in the manager of OVH. (only virtual mac can be created for block ip affected to a physical server)
I have eth1 without ip adress linked to the vrack, an vmbr3 (with private adress bridged to this eth1 interface)
For linux vm machine bridged to the vmbr3, I simply configure the network interface with an IP adresse of my bloc (with the brodcast, mask and gateway given by OVH)..Linux machine can access the internet and I can acces my linux from internet.
But ...for windows machine with the same config, no connectivity to internet, only connectivity between vm with public adress bridged to my vmbr3
any ideas ?

my proxmox network config is here after and also config of one vm linux
PROXMOX interface
auto lo
iface lo inet loopback

# for Routing
auto vmbr1
iface vmbr1 inet manual
post-up /etc/pve/
bridge_ports dummy0
bridge_stp off
bridge_fd 0

# vmbr0: Bridging. Make sure to use only MAC adresses that were assigned to you.
auto vmbr0
iface vmbr0 inet static
address 151.80.x.x
network 151.80.X.0
broadcast 151.X.X.255
gateway 151.80.X.254
bridge_ports eth0
bridge_stp off
bridge_fd 0

iface vmbr0 inet6 static
address 2001:41d0:1008:2972::
netmask 64
post-up /sbin/ip -f inet6 route add 2001:41d0:1008:29ff:ff:ff:ff:ff dev vmbr0
post-up /sbin/ip -f inet6 route add default via 2001:41d0:1008:29ff:ff:ff:ff:ff
pre-down /sbin/ip -f inet6 route del default via 2001:41d0:1008:29ff:ff:ff:ff:ff
pre-down /sbin/ip -f inet6 route del 2001:41d0:1008:29ff:ff:ff:ff:ff dev vmbr0

#network to vrack
auto eth1
iface eth1 inet manual

#bridge reseau vrack
auto vmbr3
iface vmbr3 inet static
bridge_ports eth1
bridge_stp off
bridge_fd 0

# vmbr2: Bridging. Make sure to use only MAC adresses that were assigned to you.
# private sub network with nat
auto vmbr2
iface vmbr2 inet static
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 '' -o vmbr0 -j MASQUERADE
post-down iptables -t nat -D POSTROUTING -s '' -o vmbr0 -j MASQUERADE

VM linu Interface
iface ens8 inet static
broadcast (value given by ovh)
gateway (gateway value given by ovh)
# dns-* options are implemented by the resolvconf package, if installed


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