Chapter 13. System Services

Table of Contents

A system service provides general functionality, and runs as a separate concurrent process alongside normal traffic handling.

Table 13.1 lists the services that the FB2500 can provide :-

Table 13.1. List of system services

Service	Function
SNMP server	provides clients with access to management information using the Simple Network Management Protocol
NTP client	automatically synchronises the FB2500's clock with an NTP time server (usually using an Internet public NTP server)
Telnet server	provides an administration command-line interface accessed over a network connection
HTTP server	serves the web user-interface files to a user's browser on a client machine
DNS	relays DNS requests from either the FB2500 itself, or client machines to one or more DNS resolvers
RADIUS	Configuration of RADIUS service for platform RADIUS for L2TP. Configuration of RADIUS client accessing external RADIUS servers.

Services are configured under the "Setup" category, under the heading "General system services", where there is a single services object (XML element : <services>). The services object doesn't have any attributes itself, all configuration is done via child objects, one per service. If a service object is not present, the service is disabled. Clicking on the Edit link next to the services object will take you to the lists of child objects. Where a service object is not present, the table in that section will contain an "Add" link. A maximum of one instance of each service object type can be present.

13.1. Common settings

Most system service have common access control attributes as follows.

Tip

You can verify whether the access control performs as intended using the diagnostic facility described in Section 14.2

Table 13.2. List of system services

Attribute	Function
`table`	If specified, then the service only accepts requests/connections on the specified routing table. If not specified then the service works on any routing table. Where the service is also a client then this specifies the routing table to use (default 0).
`allow`	If specified then this is a list of ranges of IP addresses and ip group names from which connections are allowed. If specified as an empty list then no access is allowed. If omitted then access is allowed from everywhere. Note that if `local-only` is specified, the allow list allows access from addresses that are not local, if they are in the `allow` list.
`local-only`	This normally defaults to `true`, but not in all cases. If true then access is only allowed from machines on IPs on the local subnet^[a] (and any addresses in the `allow` list, if specified).
`log`	The standard `log`, `log-error`, and `log-debug` settings can be used to specified levels of logging for the service.
^[a]A locally-attached subnet is one which can be directly reached via one of the defined interfaces, i.e. is not accessed via a gateway.

Tip

Address ranges in allow can be entered using either <first address>-<last_address> syntax, or using CIDR notation : <start address>/<prefix length>. If a range entered using the first syntax can be expressed using CIDR notation, it will be automatically converted to that format when the configuration is saved. You can also use name(s) of defined IP address group(s) - see Section 3.1 for discussion of address groups.