From: Philip Lai (philip.lai@xxxxxxx)
Date: Mon Jul 24 2000 - 09:27:41 GMT-3
Hi all,
ospf demand-circult again.
Before I post to this group, I have check with the archive but still can not
find a answer.
/------ISDN-----------------\
/ \
|---R2---FR---R3----|-----R4---R5---R6---|
R2-s0---s0/0-R3-e0/0---fa0/0-R4-s0/0---s0-R5-s1---s0-R6-e0
R2-R3 area3
R3-R4 area0
R4-R5 area1
R2-BRI0 area1
R5-BRI0 area1
Requirment:
In case of the FR is down, the isdn will up and R2 still have the
connectivity to other routers.
I use ospf demand-circult in the BRI of R2 and R5. It looks great and
everything is fine-- when
the FR is shut, the demand-cirult is up. When I try to "no shut" the FR,
most of the
ospf routes reappear in R2 using the serial as their next hop.
However, THERE ARE TWO ROUTES STILL POINT TO THE BRI0 INTERFACE !! They are
in the
routing table with metric 1501! although the metric for the orginial route
is 139!!
Since I only have one ISDN line and one NT1, I use the same number (ie:B1 to
B2) for the ISDN connection.
r2#
interface BRI0
ip address 132.3.15.1 255.255.255.252
encapsulation ppp
ip ospf cost 1500
dialer map ip 132.3.15.2 name r5 broadcast
dialer-group 1
isdn answer2 :1
no cdp enable
ppp authentication chap
r5#
interface BRI0
ip address 132.3.15.2 255.255.255.252
encapsulation ppp
ip ospf cost 1500
ip ospf demand-circuit
dialer map ip 132.3.15.1 name r2 broadcast 23734164:1
dialer-group 1
isdn answer1 :2
no cdp enable
ppp authentication chap
!
## When NO link fail, the BRI0:1 & BRI0:2 is down down
r2#sh ip int brief
Interface IP-Address OK? Method Status
Protocol
BRI0 132.3.15.1 YES manual up up
BRI0:1 unassigned YES unset down down
BRI0:2 unassigned YES unset down down
Ethernet0 132.3.20.1 YES manual up up
Loopback0 132.3.2.2 YES manual up up
Serial0 unassigned YES unset up up
Serial0.1 132.3.100.2 YES manual up up
## The routing table of R2 when FR is up, BRI is down.
r2# sh ip route
C 132.3.2.0/24 is directly connected, Loopback0
O IA 132.3.5.5/32 [110/139] via 132.3.100.3, 00:02:51, Serial0.1
O IA 132.3.6.6/32 [110/203] via 132.3.100.3, 00:02:51, Serial0.1
O IA 132.3.4.4/32 [110/75] via 132.3.100.3, 00:02:51, Serial0.1
O IA 132.3.3.3/32 [110/65] via 132.3.100.3, 00:02:51, Serial0.1
O 132.3.1.1/32 [110/65] via 132.3.100.1, 01:09:52, Serial0.1
C 132.3.15.0/30 is directly connected, BRI0
O 132.3.10.0/27 [110/70] via 132.3.100.1, 01:09:53, Serial0.1
C 132.3.20.0/27 is directly connected, Ethernet0
O IA 132.3.34.0/24 [110/74] via 132.3.100.3, 00:02:51, Serial0.1
O IA 132.3.45.0/24 [110/202] via 132.3.100.3, 00:02:52, Serial0.1
O E1 132.3.60.0/24 [110/222] via 132.3.100.3, 00:02:52, Serial0.1
O IA 132.3.56.0/30 [110/202] via 132.3.100.3, 00:02:52, Serial0.1
C 132.3.100.0/27 is directly connected, Serial0.1
O*E1 0.0.0.0/0 [110/203] via 132.3.100.3, 00:02:52, Serial0.1
## The routing table of R2 when FR is down, BRI is up.
r2# sh ip route
C 132.3.2.0/24 is directly connected, Loopback0
O IA 132.3.6.6/32 [110/1565] via 132.3.15.2, 00:00:03, BRI0
O IA 132.3.4.4/32 [110/1565] via 132.3.15.2, 00:00:03, BRI0
O IA 132.3.3.3/32 [110/1575] via 132.3.15.2, 00:00:03, BRI0
O IA 132.3.1.1/32 [110/1639] via 132.3.15.2, 00:00:03, BRI0
O 132.3.5.5/32 [110/1501] via 132.3.15.2, 00:00:03, BRI0
C 132.3.15.0/30 is directly connected, BRI0
C 132.3.15.2/32 is directly connected, BRI0
O IA 132.3.10.0/27 [110/1644] via 132.3.15.2, 00:00:04, BRI0
C 132.3.20.0/27 is directly connected, Ethernet0
O IA 132.3.34.0/24 [110/1574] via 132.3.15.2, 00:00:04, BRI0
O 132.3.45.0/30 [110/1628] via 132.3.15.2, 00:00:04, BRI0
O E1 132.3.60.0/24 [110/1584] via 132.3.15.2, 00:00:04, BRI0
O IA 132.3.56.0/30 [110/1564] via 132.3.15.2, 00:00:04, BRI0
O IA 132.3.100.0/27 [110/1638] via 132.3.15.2, 00:00:04, BRI0
O*E1 0.0.0.0/0 [110/1565] via 132.3.15.2, 00:00:04, BRI0
## The routing table of R2 when FR is up again, BRI is down.
C 132.3.2.0/24 is directly connected, Loopback0
O IA 132.3.6.6/32 [110/203] via 132.3.100.3, 00:00:20, Serial0.1
O IA 132.3.4.4/32 [110/75] via 132.3.100.3, 00:00:20, Serial0.1
O IA 132.3.3.3/32 [110/65] via 132.3.100.3, 00:00:20, Serial0.1
O 132.3.1.1/32 [110/65] via 132.3.100.1, 00:06:59, Serial0.1
O 132.3.5.5/32 [110/1501] via 132.3.15.2, 00:00:20, BRI0
C 132.3.15.0/30 is directly connected, BRI0
C 132.3.15.2/32 is directly connected, BRI0
O 132.3.10.0/27 [110/70] via 132.3.100.1, 00:07:00, Serial0.1
C 132.3.20.0/27 is directly connected, Ethernet0
O IA 132.3.34.0/24 [110/74] via 132.3.100.3, 00:00:21, Serial0.1
O 132.3.45.0/30 [110/1564] via 132.3.15.2, 00:00:21, BRI0
O E1 132.3.60.0/24 [110/222] via 132.3.100.3, 00:00:21, Serial0.1
O IA 132.3.56.0/30 [110/202] via 132.3.100.3, 00:00:21, Serial0.1
C 132.3.100.0/27 is directly connected, Serial0.1
O*E1 0.0.0.0/0 [110/203] via 132.3.100.3, 00:00:21, Serial0.1
r2#sh ip osp ne
Neighbor ID Pri State Dead Time Address Interface
132.3.5.5 1 FULL/ - - 132.3.15.2 BRI0
132.3.3.3 1 FULL/DR 00:00:30 132.3.100.3 Serial0.1
!!The problem is the routes 132.3.5.5/32 and 132.3.45.0/24 still pointing to
BRI0 !!!
They should be replaced by the ospf routes from serial0.1, but it isn't!
They will only diappear when I do a shut / no shut on the BRI0 of R2 !
Any comment are highly appreciated.
Rdgs,
Philip Lai
NCR Network Specialist
Phone: (852) 2859-6076 Fax: (852) 2294-3055
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:23:57 GMT-3