RE: OSPF Broadcast Network Type Running on Frame Relay Network

From: Michael Stout (michaelgstout@hotmail.com)
Date: Fri Aug 11 2006 - 21:08:24 ART


I beleive it is a requirement to have a DR/BDR on a broadcast network.
If you want to use a DR only you need to convert to a multipoint, a non
broadcast, or a multipoint nonbroadcast.

If you debug the ospf hellos and adjacencies, you'll see what im talking
about.
I seems like ospf is happy to get a DR but it goes down when the bdr is
not elected. then the cycle repeats itself.

You can increase the hello and dead interval for the nonbroadcast
networks if you are in a hurry.
When your neighbor relationship established the debug will go crazy but
it will settle down.

I just saw a cool undebug all Kron job that runs every minute if you want
to do something to protect your session.

<Mike

  --------------------------------------------------------------------

  From: "Russell Kelly (rukelly)" <rukelly@cisco.com>
  Reply-To: "Russell Kelly (rukelly)" <rukelly@cisco.com>
  To: <ccielab@groupstudy.com>
  Subject: OSPF Broadcast Network Type Running on Frame Relay Network
  Question
  Date: Sat, 12 Aug 2006 01:28:45 +0200
  Hi,

  An OSPF config question - I thought I had tried all combinations -
  but
  ran across the Issue below

  I have configured a frame relay hub and spoke (3 routers) with
  broadcast
  support on the frame-maps and have mapped all routers to each other
  (via
  the hub) like below

  Spoke eg ---
  --------------

  interface Serial0/0.134 multipoint
    ip address 187.1.134.4 255.255.255.0
    ip pim sparse-mode
    ip ospf network broadcast
    ip ospf priority 0
    frame-relay map ip 187.1.134.1 403 broadcast
    frame-relay map ip 187.1.134.3 403
    no frame-relay inverse-arp
  end

  Hub eg
  --------

  interface Serial0/0.134 multipoint
    ip address 187.1.134.4 255.255.255.0
    ip pim sparse-mode
    ip ospf network broadcast
    ip ospf priority 0
    frame-relay map ip 187.1.134.1 301 broadcast
    frame-relay map ip 187.1.134.3 304 broadcast
    no frame-relay inverse-arp
  End

  So I though I'd try something different and set the all interfaces to
  ip
  ospf network broadcast and set the ospf priority to 0 on the spokes
  and
  255 on the hub. The neighbors came up to full adjacency and the ospf
  databases looked the same (though the LSA routing bit not set was on
  some routes - why? - ) - R1 did not have any routes installed whist
  R3
  and R2 had all the opsf routes - I then changed so they were full
  mesh
  (each had a dedicated DLCI to each other) - this still did not
  work -
  note these routers can ping each other with no issues and multicast
  support was confirmed on the FR.

  Is there a rule re. hub and spoke and full mesh Frame-relay networks
  and
  running opsf network type broadcast on all routers? This works fine
  when the spokes are changed to non-broadcast and the hub left as
  broadcast (no neigbor statements configured)

  Any help or explanation greatly appreciated!!

  Russell

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