From: Brian McGahan (brian@cyscoexpert.com)
Date: Sat Feb 08 2003 - 16:21:09 GMT-3
Guys,
OSPF network type must match for routers to be adjacent.
Matching of the timers and DR/BDR election is not sufficient. Interface
type is not directly related to the establishment of adjacency; however,
certain interface types default to certain OSPF network types.
For example, multipoint non-broadcast interfaces such as
Frame-Relay and ATM main and multipoint subinterfaces default to OSPF
network non-broadcast. Point-to-point interfaces such as HDLC, and p2p
Frame-Relay and ATM interfaces default to network-type point-to-point.
Broadcast interfaces such as Ethernet and Token-Ring default to network
type Broadcast.
Here are some of the parameters that must match in order for
routers to be adjacent:
1. Network type
2. Hello/Dead interval
3. MTU (or MTU ignore)
4. Authentication
5. Area
6. Stub flags
7. Unique Router-ID's
For more information on troubleshooting OSPF adjacency:
http://www.cisco.com/en/US/tech/tk648/tk365/technologies_tech_note09186a
0080094050.shtml
http://www.cisco.com/en/US/tech/tk648/tk365/technologies_tech_note09186a
0080093f0f.shtml
HTH
Brian McGahan, CCIE #8593
Director of Design and Implementation
brian@cyscoexpert.com
CyscoExpert Corporation
Internetwork Consulting & Training
Voice: 847.674.3392
Fax: 847.674.2625
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> kym blair
> Sent: Saturday, February 08, 2003 6:18 AM
> To: ccielab@groupstudy.com; sagevadi@yahoo.co.uk
> Subject: Re: OSPF: point-to-point issue (NOT hello mismatch)
>
> Sage,
>
> There are two considerations when mixing ospf network types:
>
> (1) hello/dead intervals -- sounds like you already know how to adjust
> those
> to match
>
> (2) Use or non-use of DR/BDR
>
>
> Non-broadcast and broadcast elect DR/BDR, but have different
hello/dead
> intervals.
>
> Point-to-point and multipoint do not elect DR/BDR, and also have
different
> hello/dead intervals. Multipoint may require neighbor statements over
> NBMA
> so it knows which router to form an adjacency with.
>
> Here is a good link to start with:
>
>
http://www.cisco.com/en/US/tech/tk648/tk365/technologies_configuration_e
xa
> mple09186a0080094054.shtml
>
> HTH, Kym
>
>
>
>
>
>
>
> >From: "Georg Pauwen" <pauwen@hotmail.com>
> >Reply-To: "Georg Pauwen" <pauwen@hotmail.com>
> >To: sagevadi@yahoo.co.uk, ccielab@groupstudy.com
> >Subject: Re: OSPF: point-to-point issue (NOT hello mismatch)
> >Date: Sat, 08 Feb 2003 09:02:48 +0000
> >
> >Hello Sage,
> >
> >can you send the configs of both routers ?
> >
> >Regards,
> >
> >Georg
> >
> >
> >
> >
> >>From: Sage Vadi <sagevadi@yahoo.co.uk>
> >>Reply-To: Sage Vadi <sagevadi@yahoo.co.uk>
> >>To: ccielab@groupstudy.com
> >>Subject: OSPF: point-to-point issue (NOT hello mismatch)
> >>Date: Sat, 8 Feb 2003 07:41:27 +0000 (GMT)
> >>
> >>All,
> >>
> >>In my labs I was testing (OSPF):
> >>
> >>R1--point-to-point-------physicalSerial--R2
> >>
> >>NB: I cannot use ospf network types which is fine, so
> >>I just did map ip with dlci and neighbor statements.
> >>Adj comes up after hello adjustment.
> >>
> >>Problem is I can't see any OSPF routes on R2. This can
> >>work if I change R2 to point-to-point or R1 to
> >>multipoint.
> >>
> >>I can't find any obvious doco which states we
> >>would/could have hassles with this?
> >>
> >>rgds,
> >>Sage
> >>
> >>
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