pve-firewall.adoc

   1 ifdef::manvolnum[]
   2 PVE({manvolnum})
   3 ================
   4 include::attributes.txt[]
   5
   6 NAME
   7 ----
   8
   9 pve-firewall - The PVE Firewall Daemon
  10
  11
  12 SYNOPSYS
  13 --------
  14
  15 include::pve-firewall.8-synopsis.adoc[]
  16
  17
  18 DESCRIPTION
  19 -----------
  20 endif::manvolnum[]
  21
  22 ifndef::manvolnum[]
  23 {pve} Firewall
  24 ==============
  25 include::attributes.txt[]
  26 endif::manvolnum[]
  27
  28 // Copied from pve wiki: Revision as of 08:45, 9 November 2015
  29
  30 Proxmox VE Firewall provides an easy way to protect your IT
  31 infrastructure. You can easily setup firewall rules for all hosts
  32 inside a cluster, or define rules for virtual machines and
  33 containers. Features like firewall macros, security groups, IP sets
  34 and aliases help making that task easier.
  35
  36 While all configuration is stored on the cluster file system, the
  37 iptables based firewall runs on each cluster node, and thus provides
  38 full isolation between virtual machines. The distributed nature of
  39 this system also provides much higher bandwidth than a central
  40 firewall solution.
  41
  42 NOTE: If you enable the firewall, all traffic is blocked by default,
  43 except WebGUI(8006) and ssh(22) from your local network.
  44
  45
  46 Zones
  47 -----
  48
  49 The Proxmox VE firewall groups the network into the following logical zones:
  50
  51 Host::
  52
  53 Traffic from/to a cluster node
  54
  55 VM::
  56
  57 Traffic from/to a specific VM
  58
  59 For each zone, you can define firewall rules for incoming and/or
  60 outgoing traffic.
  61
  62
  63 Ports used by Proxmox VE
  64 ------------------------
  65
  66 * Web interface: 8006
  67 * VNC Web console: 5900-5999
  68 * SPICE proxy: 3128
  69 * sshd (used for cluster actions): 22
  70 * rpcbind: 111
  71 *  corosync multicast (if you run a cluster): 5404, 5405 UDP
  72
  73
  74 Configuration
  75 -------------
  76
  77 All firewall related configuration is stored on the proxmox cluster
  78 file system. So those files are automatically distributed to all
  79 cluster nodes, and the 'pve-firewall' service updates the underlying
  80 iptables rules automatically on any change. Any configuration can be
  81 done using the GUI (i.e. Datacenter -> Firewall -> Options tab (tabs
  82 at the bottom of the page), or on a Node -> Firewall), so the
  83 following configuration file snippets are just for completeness.
  84
  85 Cluster wide configuration is stored at:
  86
  87  /etc/pve/firewall/cluster.fw
  88
  89 The firewall is completely disabled by default, so you need to set the
  90 enable option here:
  91
  92 ----
  93 [OPTIONS]
  94 # enable firewall (cluster wide setting, default is disabled)
  95 enable: 1
  96 ----
  97
  98 The cluster wide configuration can contain the following data:
  99
 100 * IP set definitions
 101 * Alias definitions
 102 * Security group definitions
 103 * Cluster wide firewall rules for all nodes
 104
 105 VM firewall configuration is read from:
 106
 107  /etc/pve/firewall/<VMID>.fw
 108
 109 and contains the following data:
 110
 111 * IP set definitions
 112 * Alias definitions
 113 * Firewall rules for this VM
 114 * VM specific options
 115
 116 And finally, any host related configuration is read from:
 117
 118  /etc/pve/nodes/<nodename>/host.fw
 119
 120 This is useful if you want to overwrite rules from 'cluster.fw'
 121 config. You can also increase log verbosity, and set netfilter related
 122 options.
 123
 124 Enabling the Firewall for VMs and Containers
 125 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 126
 127 You need to enable the firewall on the virtual network interface configuration
 128 in addition to the general 'Enable Firewall' option in the 'Options' tab.
 129
 130 Firewall Rules
 131 ~~~~~~~~~~~~~~
 132
 133 Any firewall rule consists of a direction (`IN` or `OUT`) and an
 134 action (`ACCEPT`, `DENY`, `REJECT`). Additional options can be used to
 135 refine rule matches. Here are some examples:
 136
 137 ----
 138 [RULES]
 139
 140 #TYPE ACTION [OPTIONS]
 141 #TYPE MACRO(ACTION) [OPTIONS]
 142
 143 # -i      <INTERFACE>
 144 # -source <SOURCE>
 145 # -dest   <DEST>
 146 # -p      <PROTOCOL>
 147 # -dport  <DESTINATION_PORT>
 148 # -sport  <SOURCE_PORT>
 149
 150 IN SSH(ACCEPT) -i net0
 151 IN SSH(ACCEPT) -i net0 # a comment
 152 IN SSH(ACCEPT) -i net0 -source 192.168.2.192  # only allow SSH from 192.168.2.192
 153 IN SSH(ACCEPT) -i net0 -source 10.0.0.1-10.0.0.10 # accept SSH for ip range
 154 IN SSH(ACCEPT) -i net0 -source 10.0.0.1,10.0.0.2,10.0.0.3 #accept ssh for ip list
 155 IN SSH(ACCEPT) -i net0 -source +mynetgroup   # accept ssh for ipset mynetgroup
 156 IN SSH(ACCEPT) -i net0 -source myserveralias   #accept ssh for alias myserveralias
 157
 158 |IN SSH(ACCEPT) -i net0 # disabled rule
 159 ----
 160
 161 Security Groups
 162 ~~~~~~~~~~~~~~~
 163
 164 A security group is a collection of rules, defined at cluster level, which
 165 can be used in all VMs' rules. For example you can define a group named
 166 `webserver` with rules to open the http and https ports.
 167
 168 ----
 169 # /etc/pve/firewall/cluster.fw
 170
 171 [group webserver]
 172 IN  ACCEPT -p tcp -dport 80
 173 IN  ACCEPT -p tcp -dport 443
 174 ----
 175
 176 Then, you can add this group to a VM's firewall
 177
 178 ----
 179 # /etc/pve/firewall/<VMID>.fw
 180
 181 [RULES]
 182 GROUP webserver
 183 ----
 184
 185
 186 IP Aliases
 187 ~~~~~~~~~~
 188
 189 IP Aliases allow you to associate IP addresses of networks with a
 190 name. You can then refer to those names:
 191
 192 * inside IP set definitions
 193 * in `source` and `dest` properties of firewall rules
 194
 195 Standard IP alias `local_network`
 196 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 197
 198 This alias is automatically defined. Please use the following command
 199 to see assigned values:
 200
 201 ----
 202 # pve-firewall localnet
 203 local hostname: example
 204 local IP address: 192.168.2.100
 205 network auto detect: 192.168.0.0/20
 206 using detected local_network: 192.168.0.0/20
 207 ----
 208
 209 The firewall automatically sets up rules to allow everything needed
 210 for cluster communication (corosync, API, SSH) using this alias.
 211
 212 The user can overwrite these values in the cluster.fw alias
 213 section. If you use a single host on a public network, it is better to
 214 explicitly assign the local IP address
 215
 216 ----
 217 #  /etc/pve/firewall/cluster.fw
 218 [ALIASES]
 219 local_network 1.2.3.4 # use the single ip address
 220 ----
 221
 222 IP Sets
 223 ~~~~~~~
 224
 225 IP sets can be used to define groups of networks and hosts. You can
 226 refer to them with `+name` in the firewall rules' `source` and `dest`
 227 properties.
 228
 229 The following example allows HTTP traffic from the `management` IP
 230 set.
 231
 232  IN HTTP(ACCEPT) -source +management
 233
 234 Standard IP set `management`
 235 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 236
 237 This IP set applies only to host firewalls (not VM firewalls).  Those
 238 ips are allowed to do normal management tasks (PVE GUI, VNC, SPICE,
 239 SSH).
 240
 241 The local cluster network is automatically added to this IP set (alias
 242 `cluster_network`), to enable inter-host cluster
 243 communication. (multicast,ssh,...)
 244
 245 ----
 246 # /etc/pve/firewall/cluster.fw
 247
 248 [IPSET management]
 249 192.168.2.10
 250 192.168.2.10/24
 251 ----
 252
 253 Standard IP set 'blacklist'
 254 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 255
 256 Traffic from these ips is dropped by every host's and VM's firewall.
 257
 258 ----
 259 # /etc/pve/firewall/cluster.fw
 260
 261 [IPSET blacklist]
 262 77.240.159.182
 263 213.87.123.0/24
 264 ----
 265
 266 [[ipfilter-section]]
 267 Standard IP set 'ipfilter-net*'
 268 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 269
 270 These filters belong to a VM's network interface and are mainly used to prevent
 271 IP spoofing. If such a set exists for an interface then any outgoing traffic
 272 with a source IP not matching its interface's corresponding ipfilter set will
 273 be dropped.
 274
 275 For containers with configured IP addresses these sets, if they exist (or are
 276 activated via the general `IP Filter` option in the VM's firewall's 'options'
 277 tab), implicitly contain the associated IP addresses.
 278
 279 For both virtual machines and containers they also implicitly contain the
 280 standard MAC-derived IPv6 link-local address in order to allow the neighbor
 281 discovery protocol to work.
 282
 283 ----
 284 /etc/pve/firewall/<VMID>.fw
 285
 286 [IPSET ipfilter-net0] # only allow specified IPs on net0
 287 192.168.2.10
 288 ----
 289
 290 Services and Commands
 291 ~~~~~~~~~~~~~~~~~~~~~
 292
 293 The firewall runs two service daemons on each node:
 294
 295 * pvefw-logger: NFLOG daemon (ulogd replacement).
 296 * pve-firewall: updates iptables rules
 297
 298 There is also a CLI command named 'pve-firewall', which can be used to
 299 start and stop the firewall service:
 300
 301  # pve-firewall start
 302  # pve-firewall stop
 303
 304 To get the status use:
 305
 306  # pve-firewall status
 307
 308 The above command reads and compiles all firewall rules, so you will
 309 see warnings if your firewall configuration contains any errors.
 310
 311 If you want to see the generated iptables rules you can use:
 312
 313  # iptables-save
 314
 315 Tips and Tricks
 316 ~~~~~~~~~~~~~~~
 317
 318 How to allow FTP
 319 ^^^^^^^^^^^^^^^^
 320
 321 FTP is an old style protocol which uses port 21 and several other dynamic ports. So you
 322 need a rule to accept port 21. In addition, you need to load the 'ip_conntrack_ftp' module.
 323 So please run:
 324
 325  modprobe ip_conntrack_ftp
 326
 327 and add `ip_conntrack_ftp` to '/etc/modules' (so that it works after a reboot) .
 328
 329 Suricata IPS integration
 330 ^^^^^^^^^^^^^^^^^^^^^^^^
 331
 332 If you want to use the http://suricata-ids.org/[Suricata IPS]
 333 (Intrusion Prevention System), it's possible.
 334
 335 Packets will be forwarded to the IPS only after the firewall ACCEPTed
 336 them.
 337
 338 Rejected/Dropped firewall packets don't go to the IPS.
 339
 340 Install suricata on proxmox host:
 341
 342 ----
 343 # apt-get install suricata
 344 # modprobe nfnetlink_queue
 345 ----
 346
 347 Don't forget to add `nfnetlink_queue` to '/etc/modules' for next reboot.
 348
 349 Then, enable IPS for a specific VM with:
 350
 351 ----
 352 # /etc/pve/firewall/<VMID>.fw
 353
 354 [OPTIONS]
 355 ips: 1
 356 ips_queues: 0
 357 ----
 358
 359 `ips_queues` will bind a specific cpu queue for this VM.
 360
 361 Available queues are defined in
 362
 363 ----
 364 # /etc/default/suricata
 365 NFQUEUE=0
 366 ----
 367
 368
 369 ifdef::manvolnum[]
 370 include::copyright.adoc[]
 371 endif::manvolnum[]
 372
 373 Notes on IPv6
 374 ^^^^^^^^^^^^^
 375
 376 The firewall contains a few IPv6 specific options. One thing to note is that
 377 IPv6 does not use the ARP protocol anymore, and instead uses NDP (Neighbor
 378 Discovery Protocol) which works on IP level and thus needs IP addresses to
 379 succeed. For this purpose link-local addresses derived from the interface's MAC
 380 address are used. By default the 'NDP' option is enabled on both host and VM
 381 level to allow neighbor discovery (NDP) packets to be sent and received.
 382
 383 Beside neighbor discovery NDP is also used for a couple of other things, like
 384 autoconfiguration and advertising routers.
 385
 386 By default VMs are allowed to send out router solicitation messages (to query
 387 for a router), and to receive router advetisement packets. This allows them to
 388 use stateless auto configuration. On the other hand VMs cannot advertise
 389 themselves as routers unless the 'Allow Router Advertisement' (`radv: 1`) option
 390 is set.
 391
 392 As for the link local addresses required for NDP, there's also an 'IP Filter'
 393 (`ipfilter: 1`) option which can be enabled which has the same effect as adding
 394 an `ipfilter-net*` ipset for each of the VM's network interfaces containing the
 395 corresponding link local addresses.  (See the
 396 <<ipfilter-section,Standard IP set 'ipfilter-net*'>> section for details.)