Configure KVM Bridge in OVH Server.

HaroldM

I got server from ovh & they give me another subnet with IP's and now the gateway seems to be out of my new IP block ?

How to configure kvm bridge in the server please ?

dragon2611

Is it actually an OVH server or is it a SYS/KIMSUFI.

If it's an actual OVH machine and If you dont mind losing 3 IP's from the subnet it might be better to stuff it in Vrack otherwise you have do a load of routing hacks to deal with the out of subnet gateway and also register the MAC address of the VM's with OVH or their switches/routers will block it.

MikeA

The gateway is the main IP of your system with .254 as the last octet.

Just configure bridge like you normally would.

HaroldM

dragon2611 said: Is it actually an OVH server or is it a SYS/KIMSUFI.

it's OVH

MikeA said: The gateway is the main IP of your system with .254 as the last octet.

I try configure like this but not working ? can you help me ? do you have experience in OVH Bridge ?

exception0x876

make sure to assign a virtual mac from OVH panel to each IP, and then assign each mac to corresponding VM.

zeitgeist

I cannot help you in detail, but here is my network setup (debian/ubuntu based) on a OVH machine for a host-routed KVM setup (replace aa.bb.cc.dd etc. as appropriate. Also you may need some iptables/sysctl rules to make forwarding, proxyarp, etc. work):

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# lo: loopback network interface
auto lo
iface lo inet loopback
iface lo inet6 loopback

# eno1: primary network interface - WAN
auto eno1
iface eno1 inet static
  address         aa.bb.cc.dd
  netmask         255.255.255.0
  gateway         aa.bb.cc.254
  pointopoint     aa.bb.cc.254

iface eno1 inet6 static
  address 2001:41d0:aaaa:bbbb::1
  netmask 128

  pre-up ip -6 a flush dev eno1 mngtmpaddr

  post-up /sbin/ip -6 route add 2001:41d0:aaaa:bbff:ff:ff:ff:ff dev eno1
  post-up /sbin/ip -6 route add default via 2001:41d0:aaaa:bbff:ff:ff:ff:ff

  pre-down /sbin/ip -6 route del default via 2001:41d0:aaaa:bbff:ff:ff:ff:ff
  pre-down /sbin/ip -6 route del 2001:41d0:aaaa:bbff:ff:ff:ff:ff

#
# BRIDGES (host-only)
#

# vmbr0: routed hosting of VMs with public IPs
auto vmbr0
iface vmbr0 inet static
  address         aa.bb.cc.dd
  netmask         255.255.255.255
  bridge_ports    none
  bridge_stp      off 
  bridge_fd       0   
  bridge_maxwait  0

iface vmbr0 inet6 static
  address         2001:41d0:aaaa:bbbb::1
  netmask         64 

# vmbr1: internal LAN with private IPs (with access to LAN)
auto vmbr1
iface vmbr1 inet static
  address         10.4.30.100
  netmask         255.255.255.0
  bridge_ports    none
  bridge_stp      off
  bridge_fd       0
  bridge_maxwait  0

zeitgeist

@exception0x876 said:
make sure to assign a virtual mac from OVH panel to each IP, and then assign each mac to corresponding VM.

Btw, as far as I know, OVH only supports IPv4 for assigning virtual macs. That's why I opted for routed hosting of the VMs.

Shoaib_A

You can do it in conventional way( tons of tutorials are available online ) for which will you have to free 3 IPv4 addresses out of assigned block.The other (OVH) recommended way is very simple, all you have to do for each failover is as follows:

Suppose main IP of your server is 1.1.1.1 & your IPv4 block is 2.2.2.1/30 then for example if you assign 2.2.2.1 to your first VPS the netmask & gateway will be

IP = 2.2.2.1

Netmask = 255.255.255.255

Gateway = 1.1.1.254 ( IP of your main server but last octet ending in 254 )

Similarly for 2.2.2.2

Netmask = 255.255.255.255

Gateway = 1.1.1.254 ( IP of your main server but last octet ending in 254 )

Remember you have to generate vMac address for each IP from OVH Manager & use that in the VPS. If a VPS has more than one IPv4, then every IPv4 assigned to that VPS must have same vMac.

---

Following is a sample configuration for bridge

/etc/sysconfig/network-scripts/ifcfg-eth0 should look like

    DEVICE=eth0
    HWADDR=00:25:90:98:35:90
    IPV6INIT=yes
    IPV6_AUTOCONF=yes
    ONBOOT=yes
    BRIDGE=br0

etc/sysconfig/network-scripts/ifcfg-br0 should look like

DEVICE=br0
TYPE=Bridge
BOOTPROTO=static
IPADDR=1.1.1.1
NETMASK=255.255.255.0
GATEWAY=1.1.1.254
ONBOOT=yes

Falzo

@Shoaib_A said:

+1 , that's totally it.

if you use debian/ubuntu instead you might want to use POINTOPOINT in /etc/network/interfaces of the guest, we covered that lately in one of the proxmox threads ;-)

dragon2611

@exception0x876 said:
make sure to assign a virtual mac from OVH panel to each IP, and then assign each mac to corresponding VM.

That's why I said if it's an OVH machine and you don't mind wasting 3 IP's from the subnet just use Vrack and then it behaves like a normal subnet (They say not to use the last 3 as presumably they plan to run some kind of HSRP)