X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=pve-network.adoc;h=37667b8366880cb9a574d011723a5b99c425e397;hb=151bbda876579c0df1a3c598e17a9e43e9ff82b6;hp=d221c321d6d74a81a6b07465457295807697b932;hpb=052130090ec7b76091a27c5f00927067dbd51e52;p=pve-docs.git diff --git a/pve-network.adoc b/pve-network.adoc index d221c32..37667b8 100644 --- a/pve-network.adoc +++ b/pve-network.adoc @@ -5,20 +5,56 @@ ifdef::wiki[] :pve-toplevel: endif::wiki[] -Network configuration can be done either via the GUI, or by manually +Network configuration can be done either via the GUI, or by manually editing the file `/etc/network/interfaces`, which contains the whole network configuration. The `interfaces(5)` manual page contains the complete format description. All {pve} tools try hard to keep direct - user modifications, but using the GUI is still preferable, because it +user modifications, but using the GUI is still preferable, because it protects you from errors. -Once the network is configured, you can use the Debian traditional tools `ifup` +Once the network is configured, you can use the Debian traditional tools `ifup` and `ifdown` commands to bring interfaces up and down. -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 -you reboot the node. +Apply Network Changes +~~~~~~~~~~~~~~~~~~~~~ + +{pve} does not write changes directly to `/etc/network/interfaces`. Instead, we +write into a temporary file called `/etc/network/interfaces.new`, this way you +can do many related changes at once. This also allows to ensure your changes +are correct before applying, as a wrong network configuration may render a node +inaccessible. + +Reboot Node to apply +^^^^^^^^^^^^^^^^^^^^ + +With the default installed `ifupdown` network managing package you need to +reboot to commit any pending network changes. Most of the time, the basic {pve} +network setup is stable and does not change often, so rebooting should not be +required often. + +Reload Network with ifupdown2 +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +With the optional `ifupdown2` network managing package you also can reload the +network configuration live, without requiring a reboot. + +Since {pve} 6.1 you can apply pending network changes over the web-interface, +using the 'Apply Configuration' button in the 'Network' panel of a node. + +To install 'ifupdown2' ensure you have the latest {pve} updates installed, then + +WARNING: installing 'ifupdown2' will remove 'ifupdown', but as the removal +scripts of 'ifupdown' before version '0.8.35+pve1' have a issue where network +is fully stopped on removal footnote:[Introduced with Debian Buster: +https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=945877] you *must* ensure +that you have a up to date 'ifupdown' package version. + +For the installation itself you can then simply do: + + apt install ifupdown2 + +With that you're all set. You can also switch back to the 'ifupdown' variant at +any time, if you run into issues. Naming Conventions ~~~~~~~~~~~~~~~~~~ @@ -68,16 +104,16 @@ For more information see https://www.freedesktop.org/wiki/Software/systemd/Predi Choosing a network configuration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Depending on your current network organization and your resources you can +Depending on your current network organization and your resources you can choose either a bridged, routed, or masquerading networking setup. {pve} server in a private LAN, using an external gateway to reach the internet ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -The *Bridged* model makes the most sense in this case, and this is also +The *Bridged* model makes the most sense in this case, and this is also the default mode on new {pve} installations. -Each of your Guest system will have a virtual interface attached to the -{pve} bridge. This is similar in effect to having the Guest network card +Each of your Guest system will have a virtual interface attached to the +{pve} bridge. This is similar in effect to having the Guest network card directly connected to a new switch on your LAN, the {pve} host playing the role of the switch. @@ -91,7 +127,7 @@ what your provider allows. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ In that case the only way to get outgoing network accesses for your guest -systems is to use *Masquerading*. For incoming network access to your guests, +systems is to use *Masquerading*. For incoming network access to your guests, you will need to configure *Port Forwarding*. For further flexibility, you can configure @@ -102,9 +138,10 @@ virtual networks. Default Configuration using a Bridge ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +[thumbnail="default-network-setup-bridge.svg"] Bridges are like physical network switches implemented in software. -All VMs can share a single bridge, or you can create multiple bridges to -separate network domains. Each host can have up to 4094 bridges. +All virtual guests can share a single bridge, or you can create multiple +bridges to separate network domains. Each host can have up to 4094 bridges. The installation program creates a single bridge named `vmbr0`, which is connected to the first Ethernet card. The corresponding @@ -121,9 +158,9 @@ iface vmbr0 inet static address 192.168.10.2 netmask 255.255.255.0 gateway 192.168.10.1 - bridge_ports eno1 - bridge_stp off - bridge_fd 0 + bridge-ports eno1 + bridge-stp off + bridge-fd 0 ---- Virtual machines behave as if they were directly connected to the @@ -138,14 +175,15 @@ Most hosting providers do not support the above setup. For security reasons, they disable networking as soon as they detect multiple MAC addresses on a single interface. -TIP: Some providers allows you to register additional MACs on there -management interface. This avoids the problem, but is clumsy to +TIP: Some providers allow you to register additional MACs through their +management interface. This avoids the problem, but can be 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 interface. This makes sure that all network packets use the same MAC address. +[thumbnail="default-network-setup-routed.svg"] A common scenario is that you have a public IP (assume `198.51.100.5` for this example), and an additional IP block for your VMs (`203.0.113.16/29`). We recommend the following setup for such @@ -168,9 +206,9 @@ auto vmbr0 iface vmbr0 inet static address 203.0.113.17 netmask 255.255.255.248 - bridge_ports none - bridge_stp off - bridge_fd 0 + bridge-ports none + bridge-stp off + bridge-fd 0 ---- @@ -198,15 +236,36 @@ auto vmbr0 iface vmbr0 inet static address 10.10.10.1 netmask 255.255.255.0 - bridge_ports none - bridge_stp off - bridge_fd 0 + bridge-ports none + bridge-stp off + bridge-fd 0 - post-up echo 1 > /proc/sys/net/ipv4/ip_forward + post-up echo 1 > /proc/sys/net/ipv4/ip_forward 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 ---- +NOTE: In some masquerade setups with firewall enabled, conntrack zones might be +needed for outgoing connections. Otherwise the firewall could block outgoing +connections since they will prefer the `POSTROUTING` of the VM bridge (and not +`MASQUERADE`). + +Adding these lines in the `/etc/network/interfaces` can fix this problem: + +---- +post-up iptables -t raw -I PREROUTING -i fwbr+ -j CT --zone 1 +post-down iptables -t raw -D PREROUTING -i fwbr+ -j CT --zone 1 +---- + +For more information about this, refer to the following links: + +https://commons.wikimedia.org/wiki/File:Netfilter-packet-flow.svg[Netfilter Packet Flow] + +https://lwn.net/Articles/370152/[Patch on netdev-list introducing conntrack zones] + +https://blog.lobraun.de/2019/05/19/prox/[Blog post with a good explanation by using TRACE in the raw table] + + Linux Bond ~~~~~~~~~~ @@ -273,7 +332,7 @@ network-peers use different MAC addresses for their network packet traffic. If your switch support the LACP (IEEE 802.3ad) protocol then we recommend using -the corresponding bonding mode (802.3ad). Otherwise you should generally use the +the corresponding bonding mode (802.3ad). Otherwise you should generally use the active-backup mode. + // http://lists.linux-ha.org/pipermail/linux-ha/2013-January/046295.html If you intend to run your cluster network on the bonding interfaces, then you @@ -293,27 +352,30 @@ iface eno1 inet manual iface eno2 inet manual +iface eno3 inet manual + auto bond0 iface bond0 inet static - slaves eno1 eno2 + bond-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 + 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 + bridge-ports eno3 + bridge-stp off + bridge-fd 0 ---- +[thumbnail="default-network-setup-bond.svg"] Another possibility it to use the bond directly as bridge port. This can be used to make the guest network fault-tolerant. @@ -328,22 +390,183 @@ 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 + bond-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 + bridge-ports bond0 + bridge-stp off + bridge-fd 0 + +---- + + +VLAN 802.1Q +~~~~~~~~~~~ + +A virtual LAN (VLAN) is a broadcast domain that is partitioned and +isolated in the network at layer two. So it is possible to have +multiple networks (4096) in a physical network, each independent of +the other ones. + +Each VLAN network is identified by a number often called 'tag'. +Network packages are then 'tagged' to identify which virtual network +they belong to. + + +VLAN for Guest Networks +^^^^^^^^^^^^^^^^^^^^^^^ + +{pve} supports this setup out of the box. You can specify the VLAN tag +when you create a VM. The VLAN tag is part of the guest network +configuration. The networking layer supports different modes to +implement VLANs, depending on the bridge configuration: + +* *VLAN awareness on the Linux bridge:* +In this case, each guest's virtual network card is assigned to a VLAN tag, +which is transparently supported by the Linux bridge. +Trunk mode is also possible, but that makes configuration +in the guest necessary. + +* *"traditional" VLAN on the Linux bridge:* +In contrast to the VLAN awareness method, this method is not transparent +and creates a VLAN device with associated bridge for each VLAN. +That is, creating a guest on VLAN 5 for example, would create two +interfaces eno1.5 and vmbr0v5, which would remain until a reboot occurs. + +* *Open vSwitch VLAN:* +This mode uses the OVS VLAN feature. + +* *Guest configured VLAN:* +VLANs are assigned inside the guest. In this case, the setup is +completely done inside the guest and can not be influenced from the +outside. The benefit is that you can use more than one VLAN on a +single virtual NIC. + + +VLAN on the Host +^^^^^^^^^^^^^^^^ + +To allow host communication with an isolated network. It is possible +to apply VLAN tags to any network device (NIC, Bond, Bridge). In +general, you should configure the VLAN on the interface with the least +abstraction layers between itself and the physical NIC. + +For example, in a default configuration where you want to place +the host management address on a separate VLAN. + + +.Example: Use VLAN 5 for the {pve} management IP with traditional Linux bridge +---- +auto lo +iface lo inet loopback + +iface eno1 inet manual + +iface eno1.5 inet manual + +auto vmbr0v5 +iface vmbr0v5 inet static + address 10.10.10.2 + netmask 255.255.255.0 + gateway 10.10.10.1 + bridge-ports eno1.5 + bridge-stp off + bridge-fd 0 + +auto vmbr0 +iface vmbr0 inet manual + bridge-ports eno1 + bridge-stp off + bridge-fd 0 + +---- + +.Example: Use VLAN 5 for the {pve} management IP with VLAN aware Linux bridge +---- +auto lo +iface lo inet loopback + +iface eno1 inet manual + + +auto vmbr0.5 +iface vmbr0.5 inet static + address 10.10.10.2 + netmask 255.255.255.0 + gateway 10.10.10.1 + +auto vmbr0 +iface vmbr0 inet manual + bridge-ports eno1 + bridge-stp off + bridge-fd 0 + bridge-vlan-aware yes +---- + +The next example is the same setup but a bond is used to +make this network fail-safe. + +.Example: Use VLAN 5 with bond0 for the {pve} management IP with traditional Linux bridge +---- +auto lo +iface lo inet loopback + +iface eno1 inet manual + +iface eno2 inet manual + +auto bond0 +iface bond0 inet manual + bond-slaves eno1 eno2 + bond-miimon 100 + bond-mode 802.3ad + bond-xmit-hash-policy layer2+3 + +iface bond0.5 inet manual + +auto vmbr0v5 +iface vmbr0v5 inet static + address 10.10.10.2 + netmask 255.255.255.0 + gateway 10.10.10.1 + bridge-ports bond0.5 + bridge-stp off + bridge-fd 0 + +auto vmbr0 +iface vmbr0 inet manual + bridge-ports bond0 + bridge-stp off + bridge-fd 0 + +---- + +Disabling IPv6 on the Node +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +{pve} works correctly in all environments, irrespective of whether IPv6 is +deployed or not. We recommend leaving all settings at the provided defaults. +Should you still need to disable support for IPv6 on your node, do so by +creating an appropriate `sysctl.conf (5)` snippet file and setting the proper +https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt[sysctls], +for example adding `/etc/sysctl.d/disable-ipv6.conf` with content: + +---- +net.ipv6.conf.all.disable_ipv6 = 1 +net.ipv6.conf.default.disable_ipv6 = 1 ---- +This method is preferred to disabling the loading of the IPv6 module on the +https://www.kernel.org/doc/Documentation/networking/ipv6.rst[kernel commandline]. + //// TODO: explain IPv6 support? TODO: explain OVS