HP 3500YL User Manual

Page 242

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IP Routing Features
Configuring OSPF

[no-summary]: Where the routing switch is an ABR for a stub
area or an NSSA, this option reduces the amount of LSA
traffic entering the area from the backbone by replacing
the injection of type-3 summary routes with injection of
a type-3 default summary route. For NSSAs, this
command also disables injection of the type-7 default
external route from the backbone into the area (included
in the

metric-type operation described below).

(Default: Disabled)

For more on this topic, refer to “Not-So-Stubby-Area
(NSSA)” on page 5-52
, “Stub Area” on page 5-53, and
“Replacing Type-3 Summary LSAs and Type-7 Default
External LSAs with a Type-3 Default Route LSA” on
page 5-55

.

[metric-type < type1 | type2 >]: Used in NSSA ABRs only.
Enables injection of the type-7 default external route and
type-3 summary routes into the area instead of a type 3
default route. Also specifies the type of internal cost metric
to include in type-7 LSAs advertised for redistribution of
external routes in the NSSA. (The redistribution—or
external—cost metric is a global setting on the routing
switch set by the

default-metric command.) The metric-type

command specifies whether to include the redistribution
cost in the cost metric calculation for a type-7 default LSA
injected into the area.

type1: Calculate external route cost for a type-7 default
LSA as the sum of (1) the external route cost assigned
by the ASBR plus (2) the internal cost from the router
with traffic for the external route to the ASBR adver­
tising the route.

type2: Calculate external route cost for a type-7 default
LSA as being only the cost from the router with traffic
for the external route to the ASBR advertising the
route.

Using the

area < ospf-area-id > nssa < 0-16777215 > without

entering either

no-summary or metric-type resets the routing

switch to the state where injection of type-3 summary
routes and the type-7 default external routes is enabled
with metric-type set to

type2.

(Default: Enabled with metric-type

type2.)

Note: Different routers in the NSSA can be configured with
different

metric-type values.

5-68

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