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Interface bonding on Ubuntu 14.04

Install the required package ifenslave

$ sudo apt-get install ifenslave ethtool

To prevent issues make sure that the bonding  module is listed in the /etc/modules file. In this way the module will be loaded at boot time.

$ cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
# Parameters can be specified after the module name.

lp
rtc
bonding

Configure the network with the new bond0 interface.

$ cat /etc/network/interfaces

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

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet manual
  bond-master bond0

auto eth1
iface eth1 inet manual
  bond-master bond0

auto bond0
iface bond0 inet manual
  address 172.17.16.10
  netmask 255.255.255.0
  gateway 172.17.16.1
  bond-miimon 100
  bond-mode balance-alb
  bond-slaves eth0 eth1

I configured here with the balance-alb mode that is able to balance the outgoing and incoming traffic without any special switch support, but the network drivers must support ethtool to retrieve the speed from them.

The common bonding modes that are very used are:
– active-backup
– balance-alb
– 802.3ad

You should check the bonding documentation and the features of each mode here:

https://www.kernel.org/doc/Documentation/networking/bonding.txt

To check that the new bond0 interface is working:

$ sudo cat /proc/net/bonding/bond0 
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: adaptive load balancing
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Speed: 10000 Mbps
Duplex: full
Link Failure Count: 1
Permanent HW addr: 0c:c4:7a:34:e8:a2
Slave queue ID: 0

Slave Interface: eth1
MII Status: up
Speed: 10000 Mbps
Duplex: full
Link Failure Count: 1
Permanent HW addr: 0c:c4:7a:34:e8:a3
Slave queue ID: 0

 

 

Rename interfaces on Ubuntu 14.04

On my virtual machines I use many network interfaces, each one connected to a different vlan. I usually rename the interfaces on the guest machine with a meaningful name referring to its vlan, like eth40 for the interface that is connected to vlan 40. Until now I used to use ifrename package on my debian guests, but on Ubuntu 14.04 this packakge is not very long distributed.

To achive this I used an udev rule. Simply create the file /etc/udev/rules.d/70-persistent-net.rules with the following content, one line for each interface you want to rename:

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="b2:b3:31:58:96:59", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth40"

 

 

Now, change your /etc/network/interfaces file accordingly, reboot the guest and your interfaces should have changed.

VLAN tagging on Linux for KVM

Today, I’m going to explain my config for KVM server to get network connectivity on guests machines using tagged vlans to get independent networks. As virtual platform I am using Proxmox ve. Proxmox is a great platform to administer KVM and OpenVZ machines, actually it is based on Debian Lenny, but very soon will be available the 2.0 version based on Debian Squeeze and with many great features.

I have connected my kvm server network interfaces to two different switches and the switch ports configured in trunk mode only accepting traffic for my tagged vlans. For vlan configuration I am using vlan package in debian, rather than specify them like eth0.X, I prefer to configure them using this tool.

To install vlan package simply run:

 # apt-get install vlan

Above the two network interfaces I have configured a bond interface in active-backup mode. My /etc/network/interfaces file looks like this:

iface eth0 inet manual
iface eth1 inet manual


auto bond0
iface bond0 inet manual
        slaves eth0 eth1
        bond_miimon 100
        bond_mode active-backup

auto vlan50
iface vlan50 inet manual
        vlan_raw_device bond0

auto vlan60
iface vlan60 inet manual
       vlan_raw_device bond0

auto vlan100
iface vlan100 inet manual
       vlan_raw_device bond0


auto vmbr0
iface vmbr0 inet static
        address  172.17.16.5
        netmask  255.255.240.0
        gateway  172.17.16.1
        bridge_ports vlan100
        bridge_stp off
        bridge_fd 0

auto vmbr50
iface vmbr50 inet static
        address 0.0.0.0
        netmask 255.255.255.255
        bridge_ports vlan50
        bridge_stp off
        bridge_fd 0

auto vmbr60
iface vmbr60 inet static
        address 0.0.0.0
        netmask 255.255.255.255
        bridge_ports vlan60
        bridge_stp off
        bridge_fd 0


I have three bridges configured, vmbr0 (with vlan 100), required to access proxmox web interface, and vmbr50 and vmbr60, each of them accessing to their vlans to provide access to guests. The bridge vmbr0 is the only bridge that has an IP address configured, because is the only interface I’m going to use to access to the kvm server.

Now, it is easy to provide network connectivity to the kvm guests machines, simply you have to link their network interfaces to the bridge you want depending on, to that vlan you want they get access.

For example, part of one of my kvm machine config file looks like this:


vlan60: virtio=DE:17:7C:C3:CE:B2
vlan50: virtio=B2:0A:19:3E:72:4D

This is automatically added using proxmox ve web interface.

Rename linux network interfaces

Sometimes it can be useful to have network interfaces with an recognizable name, rather than eth0, eth1,… with which you can easily identify to which networks they are connected. For example, if you have a server connected to many networks and vlans you can identify the network/vlan based on interface name, eth50 for vlan50, eth100 for vlan100,… or you can simply rename interface to vlan50, vlan100 directly.

In Debian you should install ifrename package and create the file /etc/iftab with this format:

$ cat /etc/iftab 
eth50  mac F2:A8:C0:77:82:94
eth55  mac 4E:DF:22:FD:71:EA

In Redhat/CentOS you can rename /etc/sysconfig/network-scripts/ifcfg-eth0 to /etc/sysconfig/network-scripts/ifcfg-XXXX and edit file specifying this name. For example, I have my ifcfg-eth50 script like this:

DEVICE=eth50
NM_CONTROLLED=yes
ONBOOT=yes
HWADDR=9c:83:4f:af:a1:ec
TYPE=Ethernet
BOOTPROTO=none
IPADDR=172.16.0.19
PREFIX=23
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME=eth50
UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03
NETMASK=255.255.254.0
USERCTL=no

In Ubuntu, I did not try it but I think you can edit the file /etc/udev/rules.d/70-persistent-net.rules and change the name of interface according to its mac address.


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