From: Bhisham Bajaj (bhishambajaj@xxxxxxxxx)
Date: Sun Jan 06 2002 - 07:09:43 GMT-3
Yes I was wrong
summary-address is used to summarize routes injected
into OSPF
for my example we would have to have a static route
with a /20 bit mask to null 0
and then redistribute that static route into IGRP
thank u
Bhisham
--- Yu Kay <kaykkyu@yahoo.com> wrote:
> hello,
>
> I confuse to use "summary-address" under ospf.
> From cisco web site or books, they describe the
> commnad is inject the external into ospf domain, but
> your example is summarized it out to external
> routing
> domain.
> Please give me some hints ?
> thank you
> keith
>
>
> --- Bhisham Bajaj <bhishambajaj@yahoo.com> wrote:
> > There is a mistake in my typing
> >
> > I have used the /16 by mistake it is /20
> >
> > we can summarize network 32 to 47 /24 into one
> > network 142.1.32.0 /16
> > Know that the 142.1.32.0/16 advertisement is of
> the
> > same mask that is used by IGRP
> > The S1 interface that is in the 142.1.16.0/20
> > network
> > will
> > Advertise the network 142.1.32.0/16 to router R5
> >
> > Sorry
> > Thank u
> >
> > --- Bhisham Bajaj <bhishambajaj@yahoo.com> wrote:
> > > There are 5 routers
> > >
> > >
> > >
> > >
> > >
> >
>
R1----------R2-----------R3----------R4------------R5
> > >
> > > Area 1 Aear 0 Area 2
> IGRP
> > >
> > >
> > >
> > > R2 is the ABR for Area 1, there are 8 networks
> in
> > > Area
> > > 1
> > >
> > > 142.1.32.0/24 00100 000
> > > 142.1.33.0/24 00100 001
> > > 142.1.34.0/24 00100 010
> > > 142.1.35.0/24 00100 011
> > > 142.1.36.0/24 00100 100
> > > 142.1.37.0/24 00100 101
> > > 142.1.38.0/24 00100 110
> > > 142.1.39.0/24 00100 111
> > >
> > > We can summarize these networks into one
> network
> > > with
> > > the /21 mask
> > > And inject it into the ospf Area 0
> > > So on R2 we would use the command
> > >
> > > R2(config-router)# area 1 range 142.1.32.0
> > > 255.255.248.0
> > >
> > > So this will summarized route into Area o for
> > > networks
> > > 32 to 39
> > >
> > > Now we have network 40 to 47 in Area 0 & Area 2
> > >
> > > 142.1.40.0/24 00101 000
> > > 142.1.41.0/24 00101 001
> > > 142.1.42.0/24 00101 010
> > > 142.1.43.0/24 00101 011
> > > 142.1.44.0/24 00101 100
> > > 142.1.45.0/24 00101 101
> > > 142.1.46.0/24 00101 110
> > > 142.1.47.0/24 00101 111
> > >
> > >
> > > The R4 is a router in Area 2 and is the ASBR it
> > has
> > > S0
> > > in OSPF netork and S1 into IGRP network
> > >
> > > OSPF s0 s1 IGRP
> > >
> >
> ------------------------R4-------------------------
> > > 142.1.47.0/24 142.1.16.0/20
> > >
> > >
> > > The OSPF network is made up of 142.1.32.0 to
> > > 142.1.47.0 /24
> > > These routes have to be redistributed into IGRP
> > > witch
> > > has a net work 142.1.16.0/20
> > >
> > > The IGRP will not advertise a route with the
> same
> > > major network and different mask
> > >
> > > So we have to summarize all the ospf network
> into
> > > one
> > > /20 bit network
> > >
> > > 142.1.32.0/24 0010 0000
> > > 142.1.33.0/24 0010 0001
> > > 142.1.34.0/24 0010 0010
> > > 142.1.35.0/24 0010 0011
> > > 142.1.36.0/24 0010 0100
> > > 142.1.37.0/24 0010 0101
> > > 142.1.38.0/24 0010 0110
> > > 142.1.39.0/24 0010 0111
> > > 142.1.40.0/24 0010 1000
> > > 142.1.41.0/24 0010 1001
> > > 142.1.42.0/24 0010 1010
> > > 142.1.43.0/24 0010 1011
> > > 142.1.44.0/24 0010 1100
> > > 142.1.45.0/24 0010 1101
> > > 142.1.46.0/24 0010 1110
> > > 142.1.47.0/24 0010 1111
> > >
> > >
> > > we can summarize network 32 to 47 /24 into one
> > > network
> > >
> > > 142.1.32.0 /20
> > >
> > >
> > > ON the ASBR that I the router R4 we will have to
> > use
> > > the
> > > summary-address command so that when OSPF
> > > redistributes route into IGRP
> > > it will advertise the neworks 32 to 47 /24 as
> > 32/20
> > >
> > > R4(config-router)#summary-address 142.1.32.0
> > > 255.255.240.0
> > >
> > >
> > > Know that the 142.1.32.0/20 advertisement is of
> > the
> > > same mask that is used by IGRP
> > > The S1 interface that is in the 142.1.16.0/20
> > > network
> > > will
> > > Advertise the network 142.1.32.0/20 to router R5
>
> > > And R5 will be able to reach all the OSPF
> network
> > > with
> > > one route in its routing table
> > >
> > >
> > >
> > >
> > > HTH
> > >
> > > Bhisham
> > >
> > >
> > >
> > >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:56:17 GMT-3