From: Li Chaoyong (hughcyli@xxxxxxxxxxxxxxxxx)
Date: Fri Apr 21 2000 - 11:04:02 GMT-3
OH, MY GOD.
----- Original Message -----
From: "Derek Small (Fuse)" <dwsmall@fatkid.com>
To: "LASSERRE Grégory" <gregory.lasserre@arche.fr>; "ccielab groupstudy"
<ccielab@groupstudy.com>
Sent: Friday, April 21, 2000 9:47 PM
Subject: Re: Redisributing IGRP in OSPF (2)
> This is a typical limitation of FLSM routing protocols. With a subnet of
> the 131.1.x.x network already attached to R22, you will not be able to
teach
> R22 about subnets with any masks besides the one R2 is already using. If
I
> assume your loopback addresses all have the form, x.x.x.1, then you can
just
> use area range statements on R1 to summarize these networks (actually you
> would be making the advertisements more granular not summarizing) with an
a
> mask of /26 instead of /18. If these were real interfaces that supported
> systems with addresses that covered the enter scope of the subnet you
would
> need to add subnets for each summary-subnet, ie.
>
> area 1 range 131.1.64.0 255.255.255.192
> area 1 range 131.1.64.64 255.255.255.192
> area 1 range 131.1.64.128 255.255.255.192
> area 1 range 131.1.64.192 255.255.255.192
> area 1 range 131.1.65.0 255.255.255.192
> area 1 range 131.1.65.64 255.255.255.192
> area 1 range 131.1.65.128 255.255.255.192
> area 1 range 131.1.65.192 255.255.255.192
> .......
> ......
> area 1 range 131.1.127.192 255.255.255.192
>
> Obviously this would be a pain in the rear, but would be your only option.
> Of course in the real world, you would convert the IGRP router to OSPF, or
> add a static route, or just have enough foresight to avoid the situation
> entirely through good addressing practices.
>
> Thank You
>
> Derek Small
> dwsmall@fatkid.com
>
>
> ----- Original Message -----
> From: LASSERRE Grégory <gregory.lasserre@arche.fr>
> To: ccielab groupstudy <ccielab@groupstudy.com>
> Sent: Friday, April 21, 2000 6:56 AM
> Subject: Redisributing IGRP in OSPF (2)
>
>
> >
> > Hi everybody,
> >
> > regarding IGRP-> OSPF redistribution problem i configured the following
> > network :
> >
> > R4500 --- Eth 131.1.1.192/26 --- R1 --- Serial 131.1.
> > 1.128/26 --- R10 --- Eth 131.1.10.128/26 --- R22
> >
> > R4500 has 3 loopbacks : on networks
> > - 131.1.64.0/18
> > - 131.1.128.0/18
> > - 131.1.192.0/18
> >
> > R4500 and R1 are in area 1
> > R1 and R10 in area 0
> > R1 is ABR
> > R10 ASBR and provide mutual redistribution between OSPF and IGRP
> > R22 routing protocol is only IGRP
> >
> > And here is the Problem : R22 is not able to reach the 3 loopback
networks
> > on R4500
> >
> > As you see, in this configuration, it's not possible to solve the
problem
> > by using :
> > 1/ Area range on R1
> > 2/ Secondary Address in /16 onR1, R10, and R22
> > 3/ Neither Loopback, static routes, or ip default-network on R22
> >
> > So as for me, it seems that the only solution available is to configure
a
> > static route
> > on R22 ("ip default network" or "ip route" commands)
> >
> > However i'm not really satisfied by this.
> > Does anyone see another solution to solve this ?
> >
> > (i was thinking policy-routing or tunnelling could help. I will make
some
> > tests this week end).
> >
> > Cheers
> > Greg.
> >
> > ------------------------------------------------------------------------
> > Gregory LASSERRE Tel. : +33 1 69 18 98 53
> > Network Engineer Fax : +33 1 69 28 55 01
> > ARCHE Groupe SIEMENS Std : +33 1 69 18 32 32
> > FRANCE
> >
> > E-mail : gregory.lasserre@arche.fr
> > ------------------------------------------------------------------------
> >
> >
> >
> >
> > ------------------------------------------------------------------------
> > Gregory LASSERRE Tel. : +33 1 69 18 98 53
> > Network Engineer Fax : +33 1 69 28 55 01
> > ARCHE Groupe SIEMENS Std : +33 1 69 18 32 32
> > FRANCE
> >
> > E-mail : gregory.lasserre@arche.fr
> > ------------------------------------------------------------------------
> >
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