X-Git-Url: https://git.proxmox.com/?p=pve-docs.git;a=blobdiff_plain;f=pve-firewall.adoc;h=307966fa13927b6bd9a6ace007f1f89b0e12f283;hp=3ec1d3093feace5d1b05331a7f586565081569ea;hb=696fb448dc961b76926b8f656f0b192e537a1fba;hpb=a34d23e8cc1bd87b1368c52cc066eaeea425f078 diff --git a/pve-firewall.adoc b/pve-firewall.adoc index 3ec1d30..307966f 100644 --- a/pve-firewall.adoc +++ b/pve-firewall.adoc @@ -130,32 +130,40 @@ 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 -# -i -# -source -# -dest -# -p -# -dport -# -sport +DIRECTION MACRO(ACTION) [OPTIONS] # use predefined macro +---- + +The following options can be used to refine rule matches. + +include::pve-firewall-rules-opts.adoc[] + +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 @@ -263,6 +271,7 @@ Traffic from these ips is dropped by every host's and VM's firewall. 213.87.123.0/24 ---- +[[ipfilter-section]] Standard IP set 'ipfilter-net*' ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -369,3 +378,69 @@ ifdef::manvolnum[] 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 +<> 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 +(...) +----