IP Filter

From version 1.17, Humio includes an IP-based access control list (ACL) for outgoing connections made by actions. This is to protect Humio from being used to proxy requests into the same internal network as Humio. It also protects against actions being used, for example, to send requests to Zookeeper.

By default, this denies connections to any reserved IP address as defined by RFC 5735 and RFC 5156. This includes the standard ranges for internal networks. That means that, by default, Humio won't be able to send messages from actions to other services on the same internal network.

The syntax of the ACL list is a sequence, seperated by newlines or ;, of allow or deny actions, along with a CIDR block or all. An IP address is allowed or denied by finding the first match and applying the corresponding action. The all value matches any IP-address (i.e., IPv4 or IPv6).

Default ACL

If there is no match in the ACL list specified in the configuration parameter IP_FILTER_ACTIONS, the default ACL list will be applied. If that has no match either, the connection is allowed.

The default IP-based access control list (ACL) is as follows:

ini files
# From https://tools.ietf.org/html/rfc5735
deny 0.0.0.0/8
deny 10.0.0.0/8
deny 127.0.0.0/8
deny 169.254.0.0/16
deny 172.16.0.0/12
deny 192.0.0.0/24
deny 192.0.2.0/24
deny 192.88.99.0/24
deny 192.168.0.0/16
deny 198.18.0.0/15
deny 198.51.100.0/24
deny 203.0.113.0/24
deny 224.0.0.0/4
deny 240.0.0.0/4
deny 255.255.255.255/32

# From https://tools.ietf.org/html/rfc5156
deny ::/128
deny ::1/128
deny fe80::/10
deny fc00::/7
deny ff00::/8

To get the previous behavior of allowing all IP addresses in actions, for example, you would set IP_FILTER_ACTIONS ini the configuration file like so:

ini files
IP_FILTER_ACTIONS="allow all"

To allow only a particular IP address, say 192.168.0.16, but still keep other internal addresses blocked, you would change the configuration file to include something like this:

ini files
IP_FILTER_ACTIONS="allow 192.168.0.16"

If you want to allow only the IP address, 192.168.0.16 and block all other IP addresses, you would set the IP_FILTER_ACTIONS variable in configuration file like this:

ini files
IP_FILTER_ACTIONS="allow 192.168.0.16; deny all"