+[[sysadmin_network_configuration]]
Network Configuration
---------------------
-include::attributes.txt[]
+ifdef::wiki[]
+:pve-toplevel:
+endif::wiki[]
{pve} uses a bridged networking model. Each host can have up to 4094
bridges. Bridges are like physical network switches implemented in
aggregation". That way it is possible to build complex and flexible
virtual networks.
-Debian traditionally uses the 'ifup' and 'ifdown' commands to
-configure the network. The file '/etc/network/interfaces' contains the
-whole network setup. Please refer to to manual page ('man interfaces')
+Debian traditionally uses the `ifup` and `ifdown` commands to
+configure the network. The file `/etc/network/interfaces` contains the
+whole network setup. Please refer to to manual page (`man interfaces`)
for a complete format description.
NOTE: {pve} does not write changes directly to
-'/etc/network/interfaces'. Instead, we write into a temporary file
-called '/etc/network/interfaces.new', and commit those changes when
+`/etc/network/interfaces`. Instead, we write into a temporary file
+called `/etc/network/interfaces.new`, and commit those changes when
you reboot the node.
It is worth mentioning that you can directly edit the configuration
modifications. Using the GUI is still preferable, because it
protect you from errors.
+
Naming Conventions
~~~~~~~~~~~~~~~~~~
We currently use the following naming conventions for device names:
-* Ethernet devices: eth[N], where 0 ≤ N (`eth0`, `eth1`, ...)
+* New Ethernet devices: en*, systemd network interface names.
+
+* Legacy Ethernet devices: eth[N], where 0 ≤ N (`eth0`, `eth1`, ...)
+They are available when Proxmox VE has been updated by an earlier version.
* Bridge names: vmbr[N], where 0 ≤ N ≤ 4094 (`vmbr0` - `vmbr4094`)
* Bonds: bond[N], where 0 ≤ N (`bond0`, `bond1`, ...)
* VLANs: Simply add the VLAN number to the device name,
- separated by a period (`eth0.50`, `bond1.30`)
+ separated by a period (`eno1.50`, `bond1.30`)
This makes it easier to debug networks problems, because the device
names implies the device type.
+
+Systemd Network Interface Names
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Systemd uses the two character prefix 'en' for Ethernet network
+devices. The next characters depends on the device driver and the fact
+which schema matches first.
+
+* o<index>[n<phys_port_name>|d<dev_port>] — devices on board
+
+* s<slot>[f<function>][n<phys_port_name>|d<dev_port>] — device by hotplug id
+
+* [P<domain>]p<bus>s<slot>[f<function>][n<phys_port_name>|d<dev_port>] — devices by bus id
+
+* x<MAC> — device by MAC address
+
+The most common patterns are:
+
+* eno1 — is the first on board NIC
+
+* enp3s0f1 — is the NIC on pcibus 3 slot 0 and use the NIC function 1.
+
+For more information see https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/[Predictable Network Interface Names].
+
+
Default Configuration using a Bridge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The installation program creates a single bridge named `vmbr0`, which
-is connected to the first ethernet card `eth0`. The corresponding
-configuration in '/etc/network/interfaces' looks like this:
+is connected to the first Ethernet card `eno0`. The corresponding
+configuration in `/etc/network/interfaces` looks like this:
----
auto lo
iface lo inet loopback
-iface eth0 inet manual
+iface eno1 inet manual
auto vmbr0
iface vmbr0 inet static
address 192.168.10.2
netmask 255.255.255.0
gateway 192.168.10.1
- bridge_ports eth0
+ bridge_ports eno1
bridge_stp off
bridge_fd 0
----
management interface. This avoids the problem, but is clumsy to
configure because you need to register a MAC for each of your VMs.
-You can avoid the problem by "routing" all traffic via a single
+You can avoid the problem by ``routing'' all traffic via a single
interface. This makes sure that all network packets use the same MAC
address.
-A common scenario is that you have a public IP (assume 192.168.10.2
+A common scenario is that you have a public IP (assume `192.168.10.2`
for this example), and an additional IP block for your VMs
-(10.10.10.1/255.255.255.0). We recommend the following setup for such
+(`10.10.10.1/255.255.255.0`). We recommend the following setup for such
situations:
----
auto lo
iface lo inet loopback
-auto eth0
-iface eth0 inet static
+auto eno1
+iface eno1 inet static
address 192.168.10.2
netmask 255.255.255.0
gateway 192.168.10.1
- post-up echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp
+ post-up echo 1 > /proc/sys/net/ipv4/ip_forward
+ post-up echo 1 > /proc/sys/net/ipv4/conf/eno1/proxy_arp
auto vmbr0
----
-Masquerading (NAT) with iptables
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Masquerading (NAT) with `iptables`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In some cases you may want to use private IPs behind your Proxmox
host's true IP, and masquerade the traffic using NAT:
auto lo
iface lo inet loopback
-auto eth0
-#real IP adress
-iface eth0 inet static
+auto eno0
+#real IP address
+iface eno1 inet static
address 192.168.10.2
netmask 255.255.255.0
gateway 192.168.10.1
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 eth0 -j MASQUERADE
- post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o eth0 -j MASQUERADE
+ post-up iptables -t nat -A POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE
+ post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE
+----
+
+
+Linux Bond
+~~~~~~~~~~
+
+Bonding (also called NIC teaming or Link Aggregation) is a technique
+for binding multiple NIC's to a single network device. It is possible
+to achieve different goals, like make the network fault-tolerant,
+increase the performance or both together.
+
+High-speed hardware like Fibre Channel and the associated switching
+hardware can be quite expensive. By doing link aggregation, two NICs
+can appear as one logical interface, resulting in double speed. This
+is a native Linux kernel feature that is supported by most
+switches. If your nodes have multiple Ethernet ports, you can
+distribute your points of failure by running network cables to
+different switches and the bonded connection will failover to one
+cable or the other in case of network trouble.
+
+Aggregated links can improve live-migration delays and improve the
+speed of replication of data between Proxmox VE Cluster nodes.
+
+There are 7 modes for bonding:
+
+* *Round-robin (balance-rr):* Transmit network packets in sequential
+order from the first available network interface (NIC) slave through
+the last. This mode provides load balancing and fault tolerance.
+
+* *Active-backup (active-backup):* Only one NIC slave in the bond is
+active. A different slave becomes active if, and only if, the active
+slave fails. The single logical bonded interface's MAC address is
+externally visible on only one NIC (port) to avoid distortion in the
+network switch. This mode provides fault tolerance.
+
+* *XOR (balance-xor):* Transmit network packets based on [(source MAC
+address XOR'd with destination MAC address) modulo NIC slave
+count]. This selects the same NIC slave for each destination MAC
+address. This mode provides load balancing and fault tolerance.
+
+* *Broadcast (broadcast):* Transmit network packets on all slave
+network interfaces. This mode provides fault tolerance.
+
+* *IEEE 802.3ad Dynamic link aggregation (802.3ad)(LACP):* Creates
+aggregation groups that share the same speed and duplex
+settings. Utilizes all slave network interfaces in the active
+aggregator group according to the 802.3ad specification.
+
+* *Adaptive transmit load balancing (balance-tlb):* Linux bonding
+driver mode that does not require any special network-switch
+support. The outgoing network packet traffic is distributed according
+to the current load (computed relative to the speed) on each network
+interface slave. Incoming traffic is received by one currently
+designated slave network interface. If this receiving slave fails,
+another slave takes over the MAC address of the failed receiving
+slave.
+
+* *Adaptive load balancing (balance-alb):* Includes balance-tlb plus receive
+load balancing (rlb) for IPV4 traffic, and does not require any
+special network switch support. The receive load balancing is achieved
+by ARP negotiation. The bonding driver intercepts the ARP Replies sent
+by the local system on their way out and overwrites the source
+hardware address with the unique hardware address of one of the NIC
+slaves in the single logical bonded interface such that different
+network-peers use different MAC addresses for their network packet
+traffic.
+
+For the most setups the active-backup are the best choice or if your
+switch support LACP "IEEE 802.3ad" this mode should be preferred.
+
+The following bond configuration can be used as distributed/shared
+storage network. The benefit would be that you get more speed and the
+network will be fault-tolerant.
+
+.Example: Use bond with fixed IP address
+----
+auto lo
+iface lo inet loopback
+
+iface eno1 inet manual
+
+iface eno2 inet manual
+
+auto bond0
+iface bond0 inet static
+ slaves eno1 eno2
+ address 192.168.1.2
+ netmask 255.255.255.0
+ bond_miimon 100
+ bond_mode 802.3ad
+ bond_xmit_hash_policy layer2+3
+
+auto vmbr0
+iface vmbr0 inet static
+ address 10.10.10.2
+ netmask 255.255.255.0
+ gateway 10.10.10.1
+ bridge_ports eno1
+ bridge_stp off
+ bridge_fd 0
+
+----
+
+
+Another possibility it to use the bond directly as bridge port.
+This can be used to make the guest network fault-tolerant.
+
+.Example: Use a bond as bridge port
+----
+auto lo
+iface lo inet loopback
+
+iface eno1 inet manual
+
+iface eno2 inet manual
+
+auto bond0
+iface bond0 inet manual
+ slaves eno1 eno2
+ bond_miimon 100
+ bond_mode 802.3ad
+ bond_xmit_hash_policy layer2+3
+
+auto vmbr0
+iface vmbr0 inet static
+ address 10.10.10.2
+ netmask 255.255.255.0
+ gateway 10.10.10.1
+ bridge_ports bond0
+ bridge_stp off
+ bridge_fd 0
+
----
////
TODO: explain IPv6 support?
-TODO: explan OVS
+TODO: explain OVS
////