-include::attributes.txt[]
ifdef::manvolnum[]
PVE({manvolnum})
================
+include::attributes.txt[]
NAME
----
ifndef::manvolnum[]
{pve} Firewall
==============
+include::attributes.txt[]
endif::manvolnum[]
// Copied from pve wiki: Revision as of 08:45, 9 November 2015
config. You can also increase log verbosity, and set netfilter related
options.
-Enabling Firewall for VMs and Containers
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Enabling the Firewall for VMs and Containers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-You need to enable the firewall on the virtual network interface configuration.
+You need to enable the firewall on the virtual network interface configuration
+in addition to the general 'Enable Firewall' option in the 'Options' tab.
Firewall Rules
~~~~~~~~~~~~~~
-Any firewall rule consists of a direction (`IN` or `OUT`) and an
-action (`ACCEPT`, `DENY`, `REJECT`). Additional options can be used to
-refine rule matches. Here are some examples:
+Firewall rules consists of a direction (`IN` or `OUT`) and an
+action (`ACCEPT`, `DENY`, `REJECT`). You can also specify a macro
+name. Macros contain predifined sets of rules and options. Rules can be disabled by prefixing them with '|'.
+.Firewall rules syntax
----
[RULES]
-#TYPE ACTION [OPTIONS]
-#TYPE MACRO(ACTION) [OPTIONS]
+DIRECTION ACTION [OPTIONS]
+|DIRECTION ACTION [OPTIONS] # disabled rule
+
+DIRECTION MACRO(ACTION) [OPTIONS] # use predefined macro
+----
+
+The following options can be used to refine rule matches.
+
+include::pve-firewall-rules-opts.adoc[]
-# -i <INTERFACE>
-# -source <SOURCE>
-# -dest <DEST>
-# -p <PROTOCOL>
-# -dport <DESTINATION_PORT>
-# -sport <SOURCE_PORT>
+Here are some examples:
+----
+[RULES]
IN SSH(ACCEPT) -i net0
IN SSH(ACCEPT) -i net0 # a comment
-IN SSH(ACCEPT) -i net0 -source 192.168.2.192 # only allow SSH from 192.168.2.192
+IN SSH(ACCEPT) -i net0 -source 192.168.2.192 # only allow SSH from 192.168.2.192
IN SSH(ACCEPT) -i net0 -source 10.0.0.1-10.0.0.10 # accept SSH for ip range
IN SSH(ACCEPT) -i net0 -source 10.0.0.1,10.0.0.2,10.0.0.3 #accept ssh for ip list
-IN SSH(ACCEPT) -i net0 -source +mynetgroup # accept ssh for ipset mynetgroup
-IN SSH(ACCEPT) -i net0 -source myserveralias #accept ssh for alias myserveralias
+IN SSH(ACCEPT) -i net0 -source +mynetgroup # accept ssh for ipset mynetgroup
+IN SSH(ACCEPT) -i net0 -source myserveralias #accept ssh for alias myserveralias
|IN SSH(ACCEPT) -i net0 # disabled rule
+
+IN DROP # drop all incoming packages
+OUT ACCEPT # accept all outgoing packages
----
Security Groups
~~~~~~~~~~~~~~~
-A security group is a group a rules, defined at cluster level, which
-can be used in all VMs rules. For example you can define a group named
-`webserver` with rules to open http and https ports.
+A security group is a collection of rules, defined at cluster level, which
+can be used in all VMs' rules. For example you can define a group named
+`webserver` with rules to open the http and https ports.
----
# /etc/pve/firewall/cluster.fw
IN ACCEPT -p tcp -dport 443
----
-Then, you can add this group in a vm firewall
+Then, you can add this group to a VM's firewall
----
# /etc/pve/firewall/<VMID>.fw
IP Aliases
~~~~~~~~~~
-IP Aliases allows you to associate IP addresses of Networks with a
+IP Aliases allow you to associate IP addresses of networks with a
name. You can then refer to those names:
* inside IP set definitions
----
The firewall automatically sets up rules to allow everything needed
-for cluster communication (corosync, API, SSH).
+for cluster communication (corosync, API, SSH) using this alias.
The user can overwrite these values in the cluster.fw alias
section. If you use a single host on a public network, it is better to
~~~~~~~
IP sets can be used to define groups of networks and hosts. You can
-refer to them with `+name` in firewall rules `source` and `dest`
+refer to them with `+name` in the firewall rules' `source` and `dest`
properties.
The following example allows HTTP traffic from the `management` IP
Standard IP set 'blacklist'
^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Traffic from those ips is dropped in all hosts and VMs firewalls.
+Traffic from these ips is dropped by every host's and VM's firewall.
----
# /etc/pve/firewall/cluster.fw
213.87.123.0/24
----
-Standard IP set 'ipfilter'
-^^^^^^^^^^^^^^^^^^^^^^^^^^
+[[ipfilter-section]]
+Standard IP set 'ipfilter-net*'
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-This ipset is used to prevent ip spoofing
+These filters belong to a VM's network interface and are mainly used to prevent
+IP spoofing. If such a set exists for an interface then any outgoing traffic
+with a source IP not matching its interface's corresponding ipfilter set will
+be dropped.
+
+For containers with configured IP addresses these sets, if they exist (or are
+activated via the general `IP Filter` option in the VM's firewall's 'options'
+tab), implicitly contain the associated IP addresses.
+
+For both virtual machines and containers they also implicitly contain the
+standard MAC-derived IPv6 link-local address in order to allow the neighbor
+discovery protocol to work.
----
/etc/pve/firewall/<VMID>.fw
include::copyright.adoc[]
endif::manvolnum[]
+Notes on IPv6
+^^^^^^^^^^^^^
+
+The firewall contains a few IPv6 specific options. One thing to note is that
+IPv6 does not use the ARP protocol anymore, and instead uses NDP (Neighbor
+Discovery Protocol) which works on IP level and thus needs IP addresses to
+succeed. For this purpose link-local addresses derived from the interface's MAC
+address are used. By default the 'NDP' option is enabled on both host and VM
+level to allow neighbor discovery (NDP) packets to be sent and received.
+
+Beside neighbor discovery NDP is also used for a couple of other things, like
+autoconfiguration and advertising routers.
+
+By default VMs are allowed to send out router solicitation messages (to query
+for a router), and to receive router advetisement packets. This allows them to
+use stateless auto configuration. On the other hand VMs cannot advertise
+themselves as routers unless the 'Allow Router Advertisement' (`radv: 1`) option
+is set.
+
+As for the link local addresses required for NDP, there's also an 'IP Filter'
+(`ipfilter: 1`) option which can be enabled which has the same effect as adding
+an `ipfilter-net*` ipset for each of the VM's network interfaces containing the
+corresponding link local addresses. (See the
+<<ipfilter-section,Standard IP set 'ipfilter-net*'>> section for details.)
+
+Avoiding link-local addresses on tap and veth devices
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+With IPv6 enabled by default every interface gets a MAC-derived link local
+address. However, most devices on a typical {pve} setup are connected to a
+bridge and so the bridge is the only interface which really needs one.
+
+To disable a link local address on an interface you can set the interface's
+`disable_ipv6` sysconf variable. Despite the name, this does not prevent IPv6
+traffic from passing through the interface when routing or bridging, so the
+only noticeable effect will be the removal of the link local address.
+
+The easiest method of achieving this setting for all newly started VMs is to
+set it for the `default` interface configuration and enabling it explicitly on
+the interfaces which need it. This is also the case for other settings such as
+`forwarding`, `accept_ra` or `autoconf`.
+
+Here's a possible setup:
+----
+# /etc/sysconf.d/90-ipv6.conf
+
+net.ipv6.conf.default.forwarding = 0
+net.ipv6.conf.default.proxy_ndp = 0
+net.ipv6.conf.default.autoconf = 0
+net.ipv6.conf.default.disable_ipv6 = 1
+net.ipv6.conf.default.accept_ra = 0
+
+net.ipv6.conf.lo.disable_ipv6 = 0
+----
+
+----
+# /etc/network/interfaces
+(...)
+iface vmbr0 inet6 static
+ address fc00::31
+ netmask 16
+ gateway fc00::1
+ accept_ra 0
+ pre-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/disable_ipv6
+(...)
+----
projects / pve-docs.git / blobdiff