From: Marko Milivojevic (markom@vodafone.is)
Date: Wed Jun 13 2007 - 11:25:58 ART
Combination of point-to-point network type and shorter hello timers will be the fastest way to bring this up. There are some drawbacks with these fast hellos, especially if full BGP tables are involved (BGP convergence may make CPU's too busy to respond to hello's causing OSPF adjacencies to be broken, in turn causing BGP to drop, etc.).
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Geert Nijs
Sent: 13. jznm 2007 07:27
To: ccielab@groupstudy.com
Subject: Fastest OSPF neighbor up on a link
Hello all,
I am looking for the fastest possible neighbor up time on a simple p-t-p fiber link between switches:
SW1(core) ------- fiber ------ SW2
The link is configured as a Layer3 link and has a /31 subnet mask.
However, by default, OSPF uses the broadcast network type for this link, and therefore starts DR/BDR elections.
I now have the following options, i want the fastest possible "neighbor up" or "neighbor down".
Does Cisco have any recommendation regarding this ?
1) core switch is forced DR, edge switch is forced BDR
SW2
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf priority 1
carrier-delay msec 0
SW1
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf priority 255
carrier-delay msec 0
2) core switch is forced DR, edge switch is forced DROTHER
SW2
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf priority 0
carrier-delay msec 0
SW1
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf priority 255
carrier-delay msec 0
3) completely eliminate DR/BDR election and put interface in p-t-p mode
SW2
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf network point-to-point
carrier-delay msec 0
SW1
interface GigabitEthernet1/0/28
no switchport
ip address 10.56.158.11 255.255.255.254
ip ospf dead-interval minimal hello-multiplier 4
ip ospf network point-to-point
carrier-delay msec 0
This archive was generated by hypermail 2.1.4 : Sun Jul 01 2007 - 17:24:49 ART