gated.conf.4 (2010 09)

g
gated.conf(4) gated.conf(4)
the next hop is the current next hop of the local machine. All routing information advertised
by and received from a test peer is discarded, and all BGP routes that can be advertised are
sent back to the test peer. Metrics from EGP-derived and BGP-derived routes are forwarded in
the advertisement. Otherwise no metric is included.
Group parameters
The BGP statement has group clauses and peer subclauses. Any number of peer subclauses may be
specified within a group. A group clause usually defines default parameters for a group of peers, these
parameters apply to all subsidiary peer subclauses. Any parameters from the peer subclause may be
specified on the group clause to provide defaults for the whole group (which may be overridden for indivi-
dual peers).
Specifying peers
Within a group, BGP peers may be configured in one of two ways. They may be explicitly configured with
a peer statement, or implicitly configured with the allow statement. Both are described here:
allow
The allow clauses allows for peer connections from any addresses in the specified range of
network and mask pairs. All parameters for these peers must be configured on the group
clause. The internal peer structures are created when an incoming open request is received
and destroyed when the connection is broken. For more detail on specifying the network/mask
pairs, see the section on Route Filtering.
peer host
A peer clause configures an individual peer. Each peer inherits all parameters specified on a
group as defaults. Those default may be overridden by parameters explicitly specified on the
peer subclause.
Within each group clause, individual peers can be specified or a group of potential peers can be specified
using allow. Allow is used to specify a set of address masks. If GateD receives a BGP connection
request from any address in the set specified, it will accept it and set up a peer relationship.
Peer parameters
The BGP peer subclause allows the following parameters, which can also be specified on the group
clause. All are optional.
metricout metric
If specified, this metric is used as the primary metric on all routes sent to the specified peer(s).
This metric overrides the default metric, a metric specified on the group and any metric
specified by export policy.
localas autonomous_system
Identifies the autonomous system which GateD is representing to this group of peers.. The
default is that which has been set globally in the autonomoussystem statement.
nogendefault
Prevents GateD from generating a default route when EGP receives a valid update from its
neighbor. The default route is only generated when the gendefault option is enabled.
gateway gateway
If a network is not shared with a peer, gateway specifies a router on an attached network to
be used as the next hop router for routes received from this neighbor. This parameter is not
needed in most cases.
preference preference
Specifies the preference used for routes learned from these peers. This can differ from the
default BGP preference set in the bgp statement, so that GateD can prefer routes from one
peer, or group of peer, over others. This preference may be explicitly overridden by import pol-
icy.
preference2 preference
In the case of a preference tie, the second preference, preference2 may be used to break
the tie. The default value is 0.
lcladdr local_address
Specifies the address to be used on the local end of the TCP connection with the peer. For
external peers the local address must be on an interface which is shared with the peer or with
the gateway of the peer when the gateway parameter is used. A session with an external peer
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