Technical data

Gateway Routing Daemon (GATED) Configuration Reference
A.15 The Router Discovery Protocol
• preference specifies the preference of all Router Discovery default routes.
The default is 55.
• interface specifies the parameters that apply to physical interfaces. Note a
slight difference in convention from the rest of GATED,
interface specifies
just physical interfaces (such as LE0, EF0 and EN1). The Router Discovery
Client has no parameters that apply only to interface addresses.
The interface parameters that apply to physical interfaces are:
enable , which specifies that Router Discovery should be performed on the
specified interfaces. This is the default.
disable , which specifies that Router Discovery should not be performed
on the specified interfaces.
broadcast , which specifies that Router Solicitations should be broadcast
on the specified interfaces. This is the default if IP multicast support is
not available on this host or interface.
multicast , which specifies that Router Solicitations should be multicast
on the specified interfaces. If IP multicast is not available on this host
and interface, no solicitation will be performed. The default is to multicast
Router Solicitations if the host and interface support it, otherwise Router
Solicitations are broadcast.
quiet , which specifies that no Router Solicitations will be sent on this
interface, even though Router Discovery will be performed.
solicit , which specifies that initial Router Solicitations will be sent on
this interface. This is the default.
A.15.3 Tracing Options
The Router Discovery Client and Server support the state trace flag, which
traces various protocol occurrences.
The Router Discovery Client and Server do not directly support any packet
tracing options, tracing of router discovery packets is enabled with the ICMP
statement.
A.16 The Kernel Statement
While the kernel interface is not technically a routing protocol, it has many of the
characteristics of one, and GATED handles it similarly to one. The routes GATED
chooses to install in the kernel forwarding table are those that will actually be
used by the kernel to forward packets.
The add, delete and change operations GATED must use to update the typical
kernel forwarding table take a non-trivial amount of time. This does not present
a problem for older routing protocols (RIP, EGP), which are not particularly time
critical and do not easily handle very large numbers of routes anyway. The newer
routing protocols (OSPF, BGP) have stricter timing requirements and are often
used to process many more routes. The speed of the kernel interface becomes
critical when these protocols are used.
To prevent GATED from locking up for significant periods of time installing large
numbers of routes (up to a minute or more has been observed on real networks),
the processing of these routes is now done in batches. The size of these batches
may be controlled by the tuning parameters described below, but normally the
default parameters will provide the proper functionality.
Gateway Routing Daemon (GATED) Configuration Reference A–23