gated(ADMN)

gated -- gateway routing daemon

Synopsis

/etc/gated [ -c ] [ -C ] [ -n ] [ -N ] [ -ttrace_options ] [ -fconfig_file ] [ trace_file ]

Description

gated is a routing daemon that handles multiple routing protocols and replaces routed(ADMN) and any routing daemons that speak the EGP, OSPF, or BGP routing protocols. gated currently handles the RIP, BGP, EGP, and OSPF routing protocols. The gated process can be configured to perform all routing protocols or any combination of the five.

You can use the gdc(ADMN) command to control the operation of gated. (Note that gated must be started using the path /etc/gated, and not /usr/sbin/in.gated, or gdc will not be able to control gated.)

The command-line options are:

-c: Specifies that the configuration file will be parsed for syntax errors and then gated will exit; if there were no errors, gated will leave a dump file in /usr/tmp/gated_dump. gated does not need to be run as root to use the -c option, but it may not be possible to read the kernel routing table and interface configuration if not run as root. The -c option implies -tgeneral,kernel,nostamp. All traceoption and tracefile clauses in the configuration file will be ignored.
-C: Specifies that the configuration file will just be parsed for syntax errors. gated will exit with a status of 1 if there were any errors and 0 if there were not. gated does not need to be run as root to use the -C option, but it may not be possible to read the kernel routing table and interface configuration if not run as root. The -C option implies -tnostamp.
-n: Specifies that gated will not modify the kernel's routing table. This is used for testing gated configurations with actual routing data.
-N: Specifies that gated will not daemonize. Normally, if tracing to stderr is not specified, gated will daemonize if the parent process ID is not 1. This allows the use of an /etc/inittab-like method of invoking gated that does not have a PID of 1.
-t: Specifies a comma separated list of trace options to be enabled on startup. If no options are specified, ``general'' is assumed. No space is allowed between this option and its arguments.
This option must be used to trace events that take place before the configuration file is parsed, such as determining the interface configuration and reading routes from the kernel. The trace options are explained in greater detail in gated.conf(SFF).
-f: Use an alternate configuration file. By default, gated uses /etc/inet/gated.conf.

If on the command line a trace file is specified, or no trace options are specified, gated detaches from the terminal and runs in the background. If trace options are specified without specifying a trace file, gated assumes that tracing is desired to stderr and remains in the foreground.

Signal processing

gated catches the following signals and does special processing.

SIGHUP

Reread configuration. A SIGHUP causes gated to reread the configuration file. gated first performs a clean-up of all allocated policy structures. All BGP and EGP peers are flagged for deletion and the configuration file is reparsed.

If the reparse is successful, any BGP and EGP peers that are no longer in the configuration are shut down, and new peers are started. gated attempts to determine if changes to existing peers require a shutdown and restart.

It should also be possible to enable/disable any protocol without restarting gated.

Reconfiguration is currently disabled when OSPF is enabled; this will hopefully be fixed in a future release.

SIGINT

Snap-shot of current state. The current state of all gated tasks, timers, protocols and tables are written to /usr/tmp/gated_dump.

This is done by forking a subprocess to dump the table information so as not to impact gated's routing functions. On systems where memory management does not support copy-on-write, this will cause the gated address space to be duplicated; this may cause a noticeable impact on the system.

SIGTERM

Graceful shutdown. On receipt of a SIGTERM, gated attempts a graceful shutdown. All tasks and protocols are asked to shut down. Most will terminate immediately, the exception being EGP peers which wait for confirmation. It may be necessary to repeat the SIGTERM once or twice if this process takes too long.

All routes except interface routes, static routes marked with `retain', and routes marked with RTF_STATIC (on systems that support it, these routes are added with the route command) are removed from the kernel's routing table on receipt of a SIGTERM. The rationale behind this is that static routes provide the minimal routing to each router when gated is not running. To terminate gated with all the routes intact, use SIGKILL or SIGQUIT (which causes a core dump).

SIGUSR1

Toggle tracing. On receipt of a SIGUSR1, gated will close the trace file. A subsequent SIGUSR1 will cause it to be reopened. This will allow the file to be moved regularly.

It is not possible to use SIGUSR1 if a trace file has not been specified or tracing is being performed to stderr.

SIGUSR2

Check for interface changes. On receipt of a SIGUSR2, gated will rescan the kernel interface list looking for changes.

Files

/etc/gated: gated binary
/etc/inet/gated.conf: current gated configuration file
/etc/inet/gated.conf+: newer configuration file
/etc/inet/gated.conf-: older configuration file
/etc/inet/gated.conf--: much older configuration file
/etc/gated.pid: where gated stores its pid
/var/tmp/gated_dump: gated's state dump file
/var/tmp/%s_parse: where configuration file parse errors go
/var/tmp: where gated drops its core file

References

arp(ADMN), gated.conf(SFF), gdc(ADMN), ifconfig(ADMN), netstat(TC), ripquery(ADMN), routed(ADMN), rtquery(ADMN)

RFC 827, RFC 904, RFC 1058, RFC 1227, RFC 1245, RFC 1246, RFC 1256, RFC 1265, RFC 1266, RFC 1267, RFC 1269, RFC 1321, RFC 1370, RFC 1397, RFC 1403, RFC 1583, RFC 1723, RFC 1724, RFC 1772, RFC 1850