IPFILTER(5)IPFILTER(5)NAMEipfilter - IP packet filtering software
IP Filter is software that provides packet filtering capabilities on a
Solaris system. On a properly setup system, it can be used to build a
Solaris IP Filter is installed with the Solaris operating system. How‐
ever, packet filtering is not enabled by default. See ipf(1M) for a
procedure to enable and activate the IP Filter feature.
To simplify IP Filter configuration management, a firewall framework is
created to allow users to configure IP Filter by expressing firewall
policy at system and service level. Given the user-defined firewall
policy, the framework generates a set of IP Filter rules to enforce the
desired system behavior. Users specify system and service firewall
policies that allow or deny network traffic from certain hosts, sub‐
nets, and interface(s). The policies are translated into a set of
active IPF rules to enforce the specified firewall policies.
Users can still specify their own ipf rule file if they choose not to
take advantage of the framework. See ipf(1M) and ipf(4).
This section describes the host-based firewall framework. See
svc.ipfd(1M) for details on how to configure firewall policies.
A three-layer approach with different precedence levels helps the user
achieve the desired behaviors.
Global Default - Default system-wide firewall policy. This policy
is automatically inherited by all services unless services modify
their firewall policy.
Higher precedence than Global Default. A service's policy
allows/disallows traffic to its specific ports, regardless of
Global Default policy.
Another system-wide policy that takes precedence over the needs of
specific services in Network Services layer.
A firewall policy includes a firewall mode and an optional set of net‐
work sources. Network sources are IP addresses, subnets, and local net‐
work interfaces, from all of which a system can receive incoming traf‐
fic. The basic set of firewall modes are:
No firewall, allow all incoming traffic.
Allow all incoming traffic but deny from specified source(s).
Deny all incoming traffic but allow from specified source(s).
Layers in Detail
The first system-wide layer, Global Default, defines a firewall policy
that applies to any incoming traffic, for example, allowing or blocking
all traffic from an IP address. This makes it simple to have a policy
that blocks all incoming traffic or all incoming traffic from unwanted
The Network Services layer contains firewall policies for local pro‐
grams that provide service to remote clients, for example, telnetd,
sshd, and httpd. Each of these programs, a network service, has its own
firewall policy that controls access to its service. Initially, a ser‐
vice's policy is set to inherit Global Default policy, a "Use Global
Default" mode. This makes it simple to set a single policy, at the
Global Default layer, that can be inherited by all services.
When a service's policy is different from Global Default policy, the
service's policy has higher precedence. If Global Default policy is set
to block all traffic from a subnet, the SSH service could be configured
to allow access from certain hosts in that subnet. The set of all poli‐
cies for all network services comprises the Network Service layer.
The second system-wide layer, Global Override, has a firewall policy
that also applies to any incoming network traffic. This policy has
highest precedence and overrides policies in the other layers, specifi‐
cally overriding the needs of network services. The example is when it
is desirable to block known malicious source(s) regardless of services'
This framework leverages IP Filter functionality and is active only
when svc:/network/ipfilter is enabled and inactive when network/ipfil‐
ter is disabled. Similarly, a network service's firewall policy is only
active when that service is enabled and inactive when the service is
disabled. A system with an active firewall has IP Filter rules for each
running/enabled network service and system-wide policy(s) whose fire‐
wall mode is not None.
A user configures a firewall by setting the system-wide policies and
policy for each network service. See svc.ipfd(1M) on how to configure a
The firewall framework composes of policy configuration and a mechanism
to generate IP Filter rules from the policy and applying those rules to
get the desired IP Filter configuration. A quick summary of the design
and user interaction:
o system-wide policy(s) are stored in network/ipfilter
o network services' policies are stored in each SMF service
o a user activates a firewall by enabling network/ipfilter
o a user activates/deactivate a service's firewall by
enabling/disabling that network service
o changes to system-wide or per-service firewall policy
results in an update to the system's firewall rules
See attributes(5) for a description of the following attributes:
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
│Interface Stability │ Committed │
SEE ALSOsvcs(1), ipf(1M), ipnat(1M), svcadm(1M), svc.ipfd(1M), ipf(4),
ipnat(4), attributes(5), smf(5)
System Administration Guide: IP Services
The ipfilter service is managed by the service management facility,
smf(5), under the service identifier:
Administrative actions on this service, such as enabling, disabling, or
requesting restart, can be performed using svcadm(1M). The service's
status can be queried using the svcs(1) command.
IP Filter startup configuration files are stored in /etc/ipf.
May 20, 2009 IPFILTER(5)