From: Sean C (Upp_and_Upp@xxxxxxxxxxx)
Date: Mon May 06 2002 - 12:19:57 GMT-3
Hi Chang,
Who knows?? You're interpretation is just as valid or as crazy as mine.
And you're right on the discontiguous stuff - no-go the way I'm reading the
topology. Steven hasn't replied to multiple posts - puitting this post to
bed.
Don't be concerned on the way you read English - at least you have that
skill!! I have a hard enough time just deciphering ISDN output - let alone
trying a 2nd language. ;-)
Sean
----- Original Message -----
From: "ying chang" <ying_c@hotmail.com>
To: <Upp_and_Upp@hotmail.com>; <tron@huapi.ba.ar>; <trueccie@yahoo.com>
Cc: <ccielab@groupstudy.com>
Sent: Monday, May 06, 2002 10:20 AM
Subject: Re: ospf virtual link
> Hi Sean,
>
> When it comes to interprt the requirements, I'm in deep trouble. Yes.
other
> than they both are in area 2, Steven did not say they are connected or
not.
> If they are not connected, aren't we getting ourselves into this
> discontiguous area 2 stuff - two area 2s seperate by area 0 and area 1.
If
> this is the case, there's no phyical backup in the topology anywhere,
until
> we get into Harry Potter's magic stuff, I agree with you, we'll loose
> connectivity if we loose a link.
>
> You know, you read English from left to right, I read Chinese from top to
> down, seeing from the remote, kind of like you shaking your head and
saying
> "no, no, no..." and I'm noding my head saying "yes, yes, yes...", can this
> be why I mistakenly connect put two links together?
>
> Thanks,
> Chang
>
>
> >From: "Sean C" <Upp_and_Upp@hotmail.com>
> >To: "ying chang" <ying_c@hotmail.com>, <tron@huapi.ba.ar>,
> ><trueccie@yahoo.com>
> >CC: <ccielab@groupstudy.com>
> >Subject: Re: ospf virtual link
> >Date: Mon, 6 May 2002 09:25:22 -0400
> >
> >Hi Chang,
> >
> >The way I was reading Steven's topology, I didn't see any link between r2
> >and r3 besides the FR connection on Area 1.
> >"r1,r2,r3 connected by FR,all the interfaces on FR are on area 1"
> >
> >Your map has a Eth link between R2 and R3 - I read the description as an
> >Eth
> >link between R2 and R1.
> >"r1 and r2 have an ethernet int each, which is on area 2, r3 have an int
on
> >area 0."
> >
> >If your interpretation of Steven's description is correct, then yes, the
> >virtual-link will work. If the only link to R3 is by the frame, and R3's
> >frame fails - then they are out of luck.
> >
> >Am I reading this incorrectly?
> >Sean
> >
> >
> >
> >----- Original Message -----
> >From: "ying chang" <ying_c@hotmail.com>
> >To: <tron@huapi.ba.ar>; <trueccie@yahoo.com>
> >Cc: <ccielab@groupstudy.com>
> >Sent: Monday, May 06, 2002 8:16 AM
> >Subject: Re: ospf virtual link
> >
> >
> > > If I understand Steven's topology correctly, I cannot see why not. The
> >way
> >I
> > > see his topology is like below:
> > >
> > > R1
> > > / \
> > > A1 A1
> > > / \
> > > R2 R3---A0
> > > | |
> > > |--A2----|
> > >
> > > A1 is in the Frame Relay cloud, A2 and A0 are in LAN interfaces, if
> >R1-R3
> >FR
> > > link fails, he wants be able to reach A0 via R1-R2-R3 link. If this is
> >the
> > > case, I see it's a perfect case for virtual link between R1 and R3
just
> >by
> > > cutting the link betwwen R1-R3 link:
> > >
> > > R2:
> > >
> > > router ospf 100
> > > ...
> > > area 2 virtual-link R3's RID
> > > ...
> > >
> > > R3:
> > >
> > > router ospf 100
> > > ...
> > > area 2 virtual-link R2's RID
> > > ...
> > >
> > > Since the error message is referring to RID mismatch, I would use
"show
> >ip
> > > ospf" to find both R2 and R3's RID. I'm guessing he probably peering
R1
> >and
> > > R3 instead of R2 and R3, but I'm not sure.
> > >
> > > Actually, if you want to get fancy, you can use A1 to backup A2 as
well.
> > > i.e. A2 is the primary route for R2 to reach A0, but if A2 fails, R2
> >should
> > > be able to use A1 to reach A0.
> > >
> > > Chang
> > >
> > >
> > > >From: Carlos G Mendioroz <tron@huapi.ba.ar>
> > > >Reply-To: Carlos G Mendioroz <tron@huapi.ba.ar>
> > > >To: steven owen <trueccie@yahoo.com>
> > > >CC: Groupstudy ccielab list <ccielab@groupstudy.com>
> > > >Subject: Re: ospf virtual link
> > > >Date: Mon, 06 May 2002 07:52:00 -0300
> > > >
> > > >Steven,
> > > >virtual links are always area 0.
> > > >They are use to make up for the need of area 0 being THE
> > > >connecting area (aka backbone) and in one piece.
> > > >Tipical uses have one end in real area 0, and the other in
> > > >a remote (i.e. non directly connected) area, but it also
> > > >can be used to reattach a disconnected area 0 sector
> > > >(thus both ends lying in area 0).
> > > >
> > > >Now, answering you question, no, you can not.
> > > >(Also you need not, since it is ok for having more than
> > > >one area X at one time.)
> > > >What you do need is having area 2 directly connected to
> > > >area 0, and there you can (should) use one or two
> > > >VLs to go via area 1.
> > > >
> > > >steven owen wrote:
> > > > >
> > > > > I GOT r1,r2,r3 connected by FR,all the interfaces on
> > > > > FR are on area 1,r1 and r2 have an ethernet int each
> > > > > ,which is on area 2,r3 have an int on area 0.
> > > > > Can i build a vl between r1 ,r2 on area 2 to backup
> > > > > area 1 link if FR is down?
> > > > > and before i build vl,r1 always receives such the
> > > > > following error message:
> > > > > "%OSPF-4-ERRRCV: Received invalid packet: mismatch
> > > > > area ID, from backbone area must be virtual-link but
> > > > > not found from 20.4.1.1, FastEthernet1/0"
> > > > > but r2 doesn't have an int on area 0.Why?
> > > > >
> > > > > Thanks.
> > > > >
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