HP-UX Reference (11i v1 00/12) - 4 File Formats (vol 8)
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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man4/!!!intro.4
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g
gated.conf(4) gated.conf(4)
exact
This parameter specifies that the mask of the destination must match the supplied
mask exactly. This is used to match a network, but no subnets or hosts of that net-
work.
refines
Specifies that the mask of the destination must be more specified (longer) than the
filter mask. This is used to match subnets and/or hosts of a network, but not the net-
work.
all This entry matches anything. It is equivalent to:
0.0.0.0 mask 0.0.0.0
default
Matches the default route. To match, the address must be the default address and the mask
must be all zeros. This is equivalent to:
0.0.0.0 mask 0.0.0.0 exact
host host
Matches the specific host. To match, the address must exactly match the specified host and the
network mask must be a host mask (all ones). This is equivalent to:
host mask 255.255.255 exact
Matching AS paths
An AS path is a list of autonomous_systems that routing information has passed through to get to this
router, and an indicator of the origin of the AS path. This information can be used to prefer one path to a
destination network over another. The primary method for doing this with GateD is to specify a list of pat-
terns to be applied to AS paths when importing and exporting routes.
Each autonomous system that a route passed through prepends its AS number to the beginning of the AS
path.
The origin information details the completeness of AS path information. An origin of igp indicates the route
was learned from an interior routing protocol and is most likely complete. An origin of egp indicates the
route was learned from an exterior routing protocol that does not support AS paths (EGP for example) and
the path is most likely not complete. When the path information is definitely not complete, an origin of
incomplete is used.
AS path regular expressions are defined in RFC 1164 section 4.2.
AS path matching syntax
An AS path is matched using the following syntax.
aspath aspath_regexp origin any |([igp ][egp ][incomplete ])
This specifies that an AS matching the aspath_regexp with the specified origin is matched.
AS path regular expressions
Technically, an AS path regular expression is a regular expression with the alphabet being the set of AS
numbers. An AS path regular expression is composed of one or more AS paths expressions. An AS path
expressions is composed of AS path terms and AS path operators.
AS path terms
An AS path term is one of the following three objects:
autonomous_system
.
( aspath_regexp )
where
autonomous_system Any valid autonomous system number, from one through 65534 inclusive.
. Matches any autonomous system number.
( aspath_regexp ) Parentheses group subexpressions--an operator, such as * or ? works on a
single element or on a regular expression enclosed in parentheses
HP-UX Release 11i: December 2000 − 42 − Section 4−−113
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