RE: OSPF SPF timers

From: Michael Zuo (mzuo@ixiacom.com)
Date: Fri Sep 22 2006 - 21:16:13 ART


I think the Hello and Dead timers need to match on both side of the
adjacency, as you can see from output below, OSPF adjacency did not come
back up

picasso(config-router)#do sh ip os nei

Neighbor ID Pri State Dead Time Address
Interface
20.1.1.1 1 FULL/DR 00:00:35 10.1.1.2
Ethernet0/0
picasso(config-router)#int e0/0
picasso(config-if)#do sh ip os int e0/0
Ethernet0/0 is up, line protocol is up
  Internet Address 10.1.1.1/24, Area 0
  Process ID 1, Router ID 10.1.1.1, Network Type BROADCAST, Cost: 10
  Transmit Delay is 1 sec, State BDR, Priority 1
  Designated Router (ID) 20.1.1.1, Interface address 10.1.1.2
  Backup Designated router (ID) 10.1.1.1, Interface address 10.1.1.1
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:00
  Index 1/1, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 20.1.1.1 (Designated Router)
  Suppress hello for 0 neighbor(s)
picasso(config-if)#ip os he 1
picasso(config-if)#do clear ip os pro
Reset ALL OSPF processes? [no]: y
picasso(config-if)#
1w3d: %OSPF-5-ADJCHG: Process 1, Nbr 20.1.1.1 on Ethernet0/0 from FULL
to DOWN,
Neighbor Down: Interface down or detached
picasso(config-if)#
picasso(config-if)#

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Bajo
Sent: Wednesday, September 20, 2006 7:06 PM
To: Chris Broadway
Cc: ccielab@groupstudy.com
Subject: Re: OSPF SPF timers

No.

It is what an ospf router uses for its own SPF calculations when it
receives
topology changes. The value is not forwarded to a neighboring router.
"show
ip os" before and after the change on two neighboring routers show
different
values and still the adjacency is up.

On 9/20/06, Chris Broadway <midatlanticnet@gmail.com> wrote:
>
> Group,
>
> If I adjust OSPF SPF timers on a router, do I have to adjust any other
> routers in the network or in the area? I looked on the DOC but did
not
> find
> any "implementation considerations".
>
> -Broadway
>
>



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