Re: OSPF Demand Circuit

From: Cristian Henry H (chenry@reuna.cl)
Date: Fri Jul 04 2003 - 12:45:46 GMT-3

I think so.

"SHARMA,MOHIT (HP-Germany,ex1)" ha escrito:
>
> I think if you do not specify the broadcast keyword, the demand circuit
> would not be able to form any ospf adjacencies anyway.
> In this specific example, Cisco is denying ospf traffic as they dont want
> ospf hellos to bring up the link. This is a special case in which the two
> sites are only connected with the ISDN. Also they have a static route, on
> the remote site, so that the intersting traffic "only" will be able to bring
> up the link.
>
> Normally if you are using ospf demand circuit and you deny ospf in the
> intersting traffic, and there is a change in the ospf topolgy, ospf will try
> to bring up the link, would fail and would bring down the neighborship on
> the ISDN, even with the demand circuit configured.
>
> Please correct me if I m wrong.
>
> Hope it helps.
>
> -----Original Message-----
> From: Georg Pauwen [mailto:pauwen@hotmail.com]
> Sent: Friday, July 04, 2003 1:09 PM
> To: ccie2be@nyc.rr.com; ccielab@groupstudy.com
> Subject: Re: OSPF Demand Circuit
>
> Hello,
>
> AFAIK, the broadcast statement in the dialer map causes broadcasts to bring
> up the link, hence you need an access list denying OSPF packets in the
> dialer-list. Without the broadcast statement in the dialer map, you don4t
> need the access list.
>
> Regards,
>
> Georg
>
> >From: "ccie2be" <ccie2be@nyc.rr.com>
> >Reply-To: "ccie2be" <ccie2be@nyc.rr.com>
> >To: "Group Study" <ccielab@groupstudy.com>
> >Subject: OSPF Demand Circuit
> >Date: Fri, 4 Jul 2003 06:22:15 -0400
> >
> >Hi,
> >
> >After checking the archieves, I didn't find anything that specifically
> >addressed this question, so here goes.
> >
> >I thought that when a BRI interface is configured as an ip ospf
> >demand-circuit, it will automatically suppress ospf hello's as long as the
> >interface is configured as a p2p or p2m ospf network type.
> >
> >However, in the example at
> >http://www.cisco.com/warp/public/129/config-bri-map.html , it shows an
> >access
> >list being used to prevent ospf hello's in addition to the ip ospf
> >demand-circuit command being configured.
> >
> >Is it really necessary (or just sometimes necessary) to use an access list
> >to
> >deny ospf hello's (packets addressed to 224.0.0.5) when one side of the
> >isdn
> >circuit is configured as an ip ospf demand circuit? If so, why is that?
> >Also, if the access-list in addtion to the ip ospf demand circuit is only
> >needed in certain situations, what are those situations?
> >
> >Thanks, Jim
> >
> >
> >_______________________________________________________________________
> >You are subscribed to the GroupStudy.com CCIE R&S Discussion Group.
> >
> >Subscription information may be found at:
> >http://www.groupstudy.com/list/CCIELab.html
>
> _________________________________________________________________
> MSN Search, le moteur de recherche qui pense comme vous !
> http://search.msn.fr/worldwide.asp
>
> _______________________________________________________________________
> You are subscribed to the GroupStudy.com CCIE R&S Discussion Group.
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> You are subscribed to the GroupStudy.com CCIE R&S Discussion Group.
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html 

-- 
Cristian E. Henry
REUNA

E-mail: chenry@reuna.cl
Fono: 56-2-3370336

This archive was generated by hypermail 2.1.4 : Wed Aug 06 2003 - 06:52:24 GMT-3