Restricting connections with IP filtering

You can apply IP filtering to application clients, node clients, or transport clients, remote cluster clients, in addition to other nodes that are attempting to join the cluster.

If a node’s IP address is on the denylist, the Elasticsearch {security-features} allow the connection to Elasticsearch but it is be dropped immediately and no requests are processed.

Note

Elasticsearch installations are not designed to be publicly accessible over the Internet. IP Filtering and the other capabilities of the Elasticsearch {security-features} do not change this condition.

Enabling IP filtering ¶

The Elasticsearch {security-features} contain an access control feature that allows or rejects hosts, domains, or subnets. If the operator privileges feature is enabled, only operator users can update these settings.

You configure IP filtering by specifying the xpack.security.transport.filter.allow and xpack.security.transport.filter.deny settings in elasticsearch.yml. Allow rules take precedence over the deny rules.

Important

Unless explicitly specified, xpack.security.http.filter.* and xpack.security.remote_cluster.filter.* settings default to the corresponding xpack.security.transport.filter.* setting’s value.

			xpack.security.transport.filter.allow: "192.168.0.1"
xpack.security.transport.filter.deny: "192.168.0.0/24"

The _all keyword can be used to deny all connections that are not explicitly allowed.

			xpack.security.transport.filter.allow: [ "192.168.0.1", "192.168.0.2", "192.168.0.3", "192.168.0.4" ]
xpack.security.transport.filter.deny: _all

IP filtering configuration also support IPv6 addresses.

			xpack.security.transport.filter.allow: "2001:0db8:1234::/48"
xpack.security.transport.filter.deny: "1234:0db8:85a3:0000:0000:8a2e:0370:7334"

You can also filter by hostnames when DNS lookups are available.

			xpack.security.transport.filter.allow: localhost
xpack.security.transport.filter.deny: '*.google.com'

Disabling IP Filtering ¶

Disabling IP filtering can slightly improve performance under some conditions. To disable IP filtering entirely, set the value of the xpack.security.transport.filter.enabled setting in the elasticsearch.yml configuration file to false.

			xpack.security.transport.filter.enabled: false

You can also disable IP filtering for the transport protocol but enable it for HTTP only.

			xpack.security.transport.filter.enabled: false
xpack.security.http.filter.enabled: true

Specifying TCP transport profiles ¶

TCP transport profiles enable Elasticsearch to bind on multiple hosts. The Elasticsearch {security-features} enable you to apply different IP filtering on different profiles.

			xpack.security.transport.filter.allow: 172.16.0.0/24
xpack.security.transport.filter.deny: _all
transport.profiles.client.xpack.security.filter.allow: 192.168.0.0/24
transport.profiles.client.xpack.security.filter.deny: _all

Note

When you do not specify a profile, default is used automatically.

HTTP filtering ¶

You may want to have different IP filtering for the transport and HTTP protocols.

			xpack.security.transport.filter.allow: localhost
xpack.security.transport.filter.deny: '*.google.com'
xpack.security.http.filter.allow: 172.16.0.0/16
xpack.security.http.filter.deny: _all

Remote cluster (API key based model) filtering ¶

If other clusters connect using API key authentication for cross-cluster search or cross-cluster replication, you may want to have different IP filtering for the remote cluster server interface.

			xpack.security.remote_cluster.filter.allow: 192.168.1.0/8
xpack.security.remote_cluster.filter.deny: 192.168.0.0/16
xpack.security.transport.filter.allow: localhost
xpack.security.transport.filter.deny: '*.google.com'
xpack.security.http.filter.allow: 172.16.0.0/16
xpack.security.http.filter.deny: _all

Note

Whether IP filtering for remote cluster is enabled is controlled by xpack.security.transport.filter.enabled as well. This means filtering for the remote cluster and transport interfaces must be enabled or disabled together. But the exact allow and deny lists can be different between them.

Dynamically updating IP filter settings ¶

In case of running in an environment with highly dynamic IP addresses like cloud based hosting, it is very hard to know the IP addresses upfront when provisioning a machine. Instead of changing the configuration file and restarting the node, you can use the Cluster Update Settings API. For example:

			PUT /_cluster/settings
			{
  "persistent" : {
    "xpack.security.transport.filter.allow" : "172.16.0.0/24"
  }
}

You can also dynamically disable filtering completely:

			PUT /_cluster/settings
			{
  "persistent" : {
    "xpack.security.transport.filter.enabled" : false
  }
}

Note

In order to avoid locking yourself out of the cluster, the default bound transport address will never be denied. This means you can always SSH into a system and use curl to apply changes.