From: Brian Dennis (brian@5g.net)
Date: Wed Mar 05 2003 - 03:27:41 GMT-3
I would highly recommend reading the RFC covering OSPF demand circuits
(RFC 1793). After reading the RFC go back and read the Practical Studies
section about OSPF demand circuits. Then get a black marker and "X" out
that section of the Practical Studies book ;-)
Lastly let me show you a working example of an OSPF demand circuit in a
NSSA area that the Practical Studies books say doesn't work.
Rack4R5#wr t
Building configuration...
<snip>
hostname Rack4R5
!
interface Loopback0
ip address 5.5.5.5 255.255.255.255
!
interface BRI0/0
ip address 10.1.1.5 255.255.255.0
encapsulation ppp
ip ospf demand-circuit
dialer string 5272044
dialer-group 1
isdn switch-type basic-ni
isdn spid1 5272045
!
router ospf 1
log-adjacency-changes
area 1 nssa
network 5.5.5.5 0.0.0.0 area 0
network 10.1.1.0 0.0.0.255 area 1
!!
dialer-list 1 protocol ip permit
<snip>
Rack4R5#sho ip os int br0/0
BRI0/0 is up, line protocol is up (spoofing)
Internet Address 10.1.1.5/24, Area 1
Process ID 1, Router ID 5.5.5.5, Network Type POINT_TO_POINT, Cost:
1562
Configured as demand circuit.
Run as demand circuit.
DoNotAge LSA allowed.
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:05
Index 1/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 3
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 4.4.4.4 (Hello suppressed)
Suppress hello for 1 neighbor(s)
Rack4R5#sho ip os n
Neighbor ID Pri State Dead Time Address
Interface
4.4.4.4 1 FULL/ - - 10.1.1.4 BRI0/0
Rack4R5#sho isd act
------------------------------------------------------------------------
----
ISDN ACTIVE CALLS
------------------------------------------------------------------------
----
Call Calling Called Remote Seconds Seconds Seconds
Charges
Type Number Number Name Used Left Idle
Units/Currency
------------------------------------------------------------------------
----
------------------------------------------------------------------------
----
Rack4R5#sho ip rout
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS
inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, BRI0/0
O N2 192.168.1.0/24 [110/20] via 10.1.1.4, 00:02:37, BRI0/0
O N2 192.168.2.0/24 [110/20] via 10.1.1.4, 00:02:37, BRI0/0
Rack4R5#
Brian Dennis, CCIE #2210 (R&S/ISP Dial/Security)
brian@labforge.com
http://www.labforge.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
cebuano
Sent: Tuesday, March 04, 2003 8:41 PM
To: ccielab@groupstudy.com
Subject: OSPF Demand Circuit
Hi group.
In page 800 of Solie's book, he mentions that "If the dial link is in
Area 0...a demand circuit will not properly operate".
I have configured this and did not find any problem as far as the
operation of the demand circuit itself or OSPF. Is there something that
I am missing? I understand his point regarding using a STUB or NSSA for
the area configured as Demand Circuit. Any comments are welcome.
Below is the configuration. Thanks.
2503#S
!
hostname 2503
!
!
username 2504 password 0 cisco
!
isdn switch-type basic-ni
!
interface Loopback0
ip address 172.17.1.1 255.255.255.0
ip ospf network point-to-point
!
interface Ethernet0
ip address 172.16.1.1 255.255.255.0
no keepalive
!
interface BRI0
ip address 140.10.10.7 255.255.255.0
encapsulation ppp
ip ospf demand-circuit
dialer map ip 140.10.10.6 name 2504 broadcast 8358662
dialer-group 1
isdn switch-type basic-ni
isdn spid1 0835866101 8358661
isdn spid2 0835866301 8358663
ppp authentication chap
!
router ospf 100
network 140.10.10.0 0.0.0.255 area 0
network 172.0.0.0 0.255.255.255 area 0
!
dialer-list 1 protocol ip permit
!
2504#s
!
hostname 2504
!
!
username 2503 password 0 cisco
!
isdn switch-type basic-ni
!
interface Loopback0
ip address 172.22.1.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback1
ip address 172.22.53.105 255.255.255.0
ip ospf network point-to-point
!
interface BRI0
ip address 140.10.10.6 255.255.255.0
encapsulation ppp
dialer map ip 140.10.10.7 name 2503 broadcast 8358661
dialer-group 1
isdn switch-type basic-ni
isdn spid1 0835866201 8358662
isdn spid2 0835866401 8358664
!
router ospf 100
log-adjacency-changes
network 140.10.10.0 0.0.0.255 area 0
network 172.22.0.0 0.0.255.255 area 0
!
dialer-list 1 protocol ip permit
!
This archive was generated by hypermail 2.1.4 : Sat Apr 05 2003 - 08:51:32 GMT-3