From: Bashir Sulaiman (bashir.sulaiman@netwise.co.uk)
Date: Mon Nov 04 2002 - 10:30:38 GMT-3
Benny,
Without the 'ip ospf network point-to-point' statement on the loopback
interfaces, OSPF treats loopback interface as a stub network and therefore
you will see the address as x.x.x.x/32 (host route).  Hence the:
----------------------------------------------------------------------------
----------------------------------
R1 routing table:
     172.16.0.0/32 is subnetted, 2 subnets
O IA    172.16.1.1 [110/11] via 150.50.7.6, 01:03:20, Ethernet0
O IA    172.16.2.1 [110/11] via 150.50.7.6, 01:03:20, Ethernet0
----------------------------------------------------------------------------
-----------------------------------
So, you should configure:
Inter lo0
Ip adder x.x.x.x 255.255.255.0
'ip ospf network point-to-point'
inter lo1
Ip adder y.y.y.y 255.255.255.0
'ip ospf network point-to-point'
  Hope this helps
Bashir
 -----Original Message-----
From: 	nobody@groupstudy.com [mailto:nobody@groupstudy.com]  On Behalf Of
Benny Chong
Sent:	02 November 2002 02:54
To:	ccielab@groupstudy.com
Subject:	OSPF --- subnet mask of IA routes
Hi,
R1 and R2 in area 0, R2 has 2 loopback interface with ip address 
172.16.1.1/24 and 172.16.2.1/24.  I don't understand when R1 learned about 
this two loopback interfaces, it doesn't learn the network 172.16.1.0/24 and
172.16.2.0/24, but it learns 172.16.1.1 and 172.16.2.1 instead?   I use 
'network 172.16.1.0 0.0.0.255 area 4' and 'network 172.16.2.0 0.0.0.255 area
4) on R2.
R1----------R2 (lo1 and lo2 area 4)
     area 0
The question require that R1 learns these two subnets with a /24 mask, and 
the solution require configure 'ip ospf network point-to-point' under the 
two loopback interfaces in R2.  Can someone kindly explain to me? Thanks a 
lot!
Benny
**********************************************************************
'show ip ospf database' in R1:
                Summary Net Link States (Area 0)
Link ID         ADV Router      Age         Seq#       Checksum
172.16.1.1      200.0.0.6       665         0x80000003 0xC1EA
172.16.2.1      200.0.0.6       665         0x80000003 0xB6F4
R2 routing table:
     172.16.0.0/24 is subnetted, 2 subnets
C       172.16.1.0 is directly connected, Loopback1
C       172.16.2.0 is directly connected, Loopback2
R1 routing table:
     172.16.0.0/32 is subnetted, 2 subnets
O IA    172.16.1.1 [110/11] via 150.50.7.6, 01:03:20, Ethernet0
O IA    172.16.2.1 [110/11] via 150.50.7.6, 01:03:20, Ethernet0
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