From: Carlos G Mendioroz (tron@xxxxxxxxxxx)
Date: Tue Jul 30 2002 - 14:20:28 GMT-3
Krzysztof is right, this will not work if you have default route,
but even that could be solved, if we could relax a bit lab game rules.
The dependency comes from the fact that the tunnel protocol state
(up/down) is tied to destination reachability (i.e. is the destination
address in the route table ?)
The way to solve it is to put a floating static for the "watched"
network
pointing to null 0.
The method does (appart from the said inconvinience) track the
availability
of the destination, not the state of any interface, so it does work in
your
proposed scenario...
"Volkov, Dmitry (Toronto - BCE)" wrote:
>
> Krzysztof ,
>
> Sorry, I didn't understand, what are the dependencies on default-route ?
>
> Let say we have the following
>
> R3(e0)---------(e0)R1 ---isdn----R2(s0)----(s0)R3
>
> In case of link R2-----R3 goes down and network between R2 & R3 flushes from
> routing table,
> I want to bring up isdn between R1 & R2. No Dialer Watch or static routes
> are allowed.
>
> As far as I understand method proposed by Carlos:
> to put tunnel between R1 and R3 (terminate on S0) and make isdn int on R1 as
> backup for tunnel
> If s0 goes down, tunnel goes down and R1 will dial R2. Am I right ?
>
> What is special about default-route here ?
>
> Unfortunately this scenario will not work in case of multipoint Frame link
> between R1 & R2, as it monitors only interface status
> and doesn't monitor of existence of route to network between R2 & R3.
>
> Thanks,
>
> Dmitry
>
> -----Original Message-----
> From: Horszczaruk Krzysztof [mailto:Krzysztof.Horszczaruk@getronics.com]
> Sent: Tuesday, July 30, 2002 11:24 AM
> To: Carlos G Mendioroz; Volkov, Dmitry (Toronto - BCE)
> Cc: ccielab@groupstudy.com
> Subject: RE: other way to monitor deleted route than dialer Watch
>
> many magic things can be made with tunnel ...
>
> this one (invented by Carlos) would work provided there is no default-route.
> am i right ?
> (in case of default-route the fake tunnel will stay permanently up)
>
> krzysztof horszczaruk
>
> >>>-----Original Message-----
> >>>From: Carlos G Mendioroz [mailto:tron@huapi.ba.ar]
> >>>Sent: Tuesday, July 30, 2002 4:51 PM
> >>>To: Volkov, Dmitry (Toronto - BCE)
> >>>Cc: 'ccielab@groupstudy.com'
> >>>Subject: Re: other way to monitor deleted route than dialer Watch
> >>>
> >>>
> >>>Yes,
> >>>you can combine a fake tunnel endpoint and backup to achieve the
> >>>same functionality. A tunnel goes down when there's no route to
> >>>the other side. Backup on it will keep down an ISDN down for
> >>>as long as the remote is reachable. Add some interesting traffic
> >>>to the mix to get a homebrew dialer watch recipe! :-)
> >>>
> >>>
> >>>
> >>>"Volkov, Dmitry (Toronto - BCE)" wrote:
> >>>>
> >>>> Hello group,
> >>>>
> >>>> Does anybody know the way (other than Dialer Watch) to
> >>>monitor the existence
> >>>> of a specified route
> >>>> and if that route is not present, to initate dialing of
> >>>the backup link ???
> >>>>
> >>>> Is it possible to monitor deleted (not connected) route to
> >>>make ISDN dial
> >>>> using something else than Dialer Watch ?
> >>>>
> >>>> Let say I want do make call to provide backup when some
> >>>link (not connected)
> >>>> goes down.
> >>>>
> >>>> Thanks,
> >>>>
> >>>> Dmitry
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