From: Gerry Hilton (gerry.hilton@rogers.com)
Date: Wed Mar 05 2003 - 13:37:44 GMT-3
Hi. It turns out that this problem doesn't happen if I don't use ppp
encapsulation. While trying the suggestion of changing the ospf mask to
0.0.0.1 I found the problem would not occur with either 0.0.0.0 or
0.0.0.1, if the encapsulation on BRI 0 was left at the default. With
the default encapsulation, no route to 15.5.5.5 was installed after the
primary was down. With ppp encapsulation, in either case the directly
connected route to 15.5.5.5 via BRI0 was installed, meaning that BRI 0
would never drop.
Primay down, no ppp encapsulation:
router4-1750-1#sh ip route
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
14.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 14.30.0.4/32 is directly connected, Loopback0
C 14.40.0.0/24 is directly connected, BRI0
Primary down, ppp encapsulation:
router4-1750-1#sh ip route
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
14.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 14.30.0.4/32 is directly connected, Loopback0
C 14.40.0.0/24 is directly connected, BRI0
15.0.0.0/32 is subnetted, 1 subnets
C 15.5.5.5 is directly connected, BRI0
Thanks,
Gerry
tan wrote:
>Hi Gerry,
>
>I see you got a few replies already and solved the problem. I'll add in late
>though that the original problem of the configs you posted is not because
>the loopback is /32, but maybe a bug posted by Mas Kato (fixed in 12.2). The
>question isn't why doesn't your link come down, but why your router sees a
>far ospf route 15.5.5.5 as directly connected. Why does an ospf route come
>in over isdn, then get installed as directly connected? The route will never
>go down or get replaced by another route. Dialer watch would time out and
>not keep it up, but the routing table will forward all traffic to it so the
>idle timer would never run down. Sounds reasonable at least.
>
>If I recall correctly, on an ASBR if you advertise a route in ospf with
>0.0.0.0 wildcard (which you did in bottom config), then the forwarding
>address bit is not set or something. Then the receiver sets the forwarding
>address to itself, its RID, and installs in its route table with next hop of
>itself. Which would get interpreted as directly connected by route table.
>Hm, a bit odd, but I think this might be how the 15.5.5.5 over the isdn came
>to be regarded as directly connected by the local router. The thing I don't
>understand is, why doesn't it also happen when it comes across the serial
>link before link goes down originally.
>
>To fix/test this, leave it as /32 and change the ospf mask to 0.0.0.1 then
>show us the route table on the local router after the serial link goes down.
>I'm curious what the result is.
>
>Cheers
>
>
>
>>-----Original Message-----
>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>>Gerry Hilton
>>Sent: Wednesday, March 05, 2003 3:22 AM
>>To: ccielab@groupstudy.com
>>Subject: Dialer watch - BRI interface won't go down when
>>primary is back
>>up
>>
>>
>>Hi. I know this issue has been raised before as I searched the
>>archives. However, I did not find a solution that solves the problem
>>that I am seeing.
>>
>>The problem is that the BRI interface will not drop after the primary
>>interface goes back up, as it thinks that the primary is
>>still down (as
>>indicated by debug dialer). I believe this has to do with
>>the way that
>>the routing table changes after the primary interface is shut down.
>> Instead of showing as via OSPF or EIGRP, it shows as directley
>>connected to BRI0. Bringing the primary interface up again doesn't
>>change this. The only way to fix this is to shut down BRI0, which
>>causes the routing table to change and then dialer debug shows the
>>primary as up again.
>>
>>The version on each router is Version 12.1(17)
>>.
>>Thanks for any help,
>> Gerry
>>
>>Details and config follow:
>>
>>The route being watched is 15.5.5.5. It has the appropriate map
>>statement under BRI0. The primary is S0.
>>
>>
>>router4-1750-1#sh ip route
>>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 14.70.0.7 to network 0.0.0.0
>>
>> 14.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
>>C 14.30.0.4/32 is directly connected, Loopback0
>>C 14.40.0.0/24 is directly connected, BRI0
>>O 14.37.0.7/32 [110/2] via 14.70.0.7, 00:02:01, Serial0
>>C 14.70.0.0/24 is directly connected, Serial0
>> 15.0.0.0/32 is subnetted, 1 subnets
>>O 15.5.5.5 [110/2] via 14.70.0.7, 00:02:01, Serial0
>>O*E2 0.0.0.0/0 [110/1] via 14.70.0.7, 00:02:01, Serial0
>>
>>Once S0 is shut down, the routing table changes and remains in this
>>state even when S0 is brought back up:
>>
>>router4-1750-1#sh ip route
>>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
>>
>> 14.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
>>C 14.30.0.4/32 is directly connected, Loopback0
>>C 14.40.0.0/24 is directly connected, BRI0
>> 15.0.0.0/32 is subnetted, 1 subnets
>>C 15.5.5.5 is directly connected, BRI0
>>router4-1750-1#
>>
>>debug dialer event and debug dialer packet shows the primary as down
>>even when S0 is brought up:
>>
>>router4-1750-1#
>>*Mar 2 05:40:44: %OSPF-5-ADJCHG: Process 1, Nbr 14.37.0.7 on Serial0
>>from LOADING to FULL, Loading Done
>>router4-1750-1#
>>1d05h: BR0:1 DDR: idle timeout
>>1d05h: DDR: Dialer Watch: watch-group = 8
>>1d05h: DDR: network 15.5.5.5/255.255.255.255 UP,
>>1d05h: DDR: primary DOWN
>>router4-1750-1#
>>1d05h: BR0 DDR: ip (s=14.40.0.4, d=224.0.0.5), 64 bytes, outgoing
>>uninteresting (list 101)
>>1d05h: BR0 DDR: sending broadcast to ip 15.5.5.5
>>1d05h: BR0 DDR: sending broadcast to ip 14.40.0.7 -- succeeded
>>router4-1750-1#
>>1d05h: BR0:1 DDR: idle timeout
>>1d05h: DDR: Dialer Watch: watch-group = 8
>>1d05h: DDR: network 15.5.5.5/255.255.255.255 UP,
>>1d05h: DDR: primary DOWN
>>router4-1750-1#
>>1d05h: BR0 DDR: ip (s=14.40.0.4, d=224.0.0.5), 64 bytes, outgoing
>>uninteresting (list 101)
>>1d05h: BR0 DDR: sending broadcast to ip 15.5.5.5
>>1d05h: BR0 DDR: sending broadcast to ip 14.40.0.7 -- succeeded
>>router4-1750-1#
>>
>>Manually shutting down BRI0 results in the primary (S0) being
>>shown as
>>up, although it was already:
>>
>>1d05h: BR0:1 DDR: disconnecting call
>>1d05h: DDR: Dialer Watch: watch-group = 8
>>1d05h: DDR: network 15.5.5.5/255.255.255.255 UP,
>>1d05h: DDR: primary UP
>>*Mar 2 05:41:30: %LINK-3-UPDOWN: Interface BRI0:2, changed
>>state to down
>>1d05h: BR0:2 DDR: disconnecting call
>>1d05h: DDR: Dialer Watch: watch-group = 8
>>1d05h: DDR: network 15.5.5.5/255.255.255.255 UP,
>>1d05h: DDR: primary UP
>>*Mar 2 05:41:31: %LINEPROTO-5-UPDOWN: Line protocol on Interface
>>BRI0:1, changed state to down
>>
>>Configs:
>>
>>Calling router:
>>
>>router4-1750-1#sh ver
>>Cisco Internetwork Operating System Software
>>IOS (tm) C1700 Software (C1700-BNO3R2SV3Y56I-M), Version 12.1(17),
>>RELEASE SOFTWARE (fc1)
>>
>>
>>router4-1750-1#sh ru
>>Building configuration...
>>
>>Current configuration : 1722 bytes
>>!
>>version 12.1
>>no service single-slot-reload-enable
>>service timestamps debug uptime
>>service timestamps log datetime
>>no service password-encryption
>>!
>>hostname router4-1750-1
>>!
>>logging buffered 10000 debugging
>>!
>>username zz privilege 15 nopassword
>>username router7-1750-2 password 0 ipexpert
>>!
>>!
>>!
>>!
>>memory-size iomem 25
>>ip subnet-zero
>>no ip domain-lookup
>>!
>>ip audit notify log
>>ip audit po max-events 100
>>ip multicast-routing
>>isdn switch-type basic-ni
>>!
>>!
>>!
>>!
>>voice-port 2/0
>>!
>>voice-port 2/1
>>!
>>!
>>!
>>!
>>interface Loopback0
>> ip address 14.30.0.4 255.255.255.255
>> ip ospf network point-to-point
>>!
>>interface Loopback1
>> no ip address
>>!
>>interface Serial0
>> ip address 14.70.0.4 255.255.255.0
>> clockrate 148000
>>!
>>interface BRI0
>> ip address 14.40.0.4 255.255.255.0
>> encapsulation ppp
>> dialer idle-timeout 10
>> dialer watch-disable 2
>> dialer map ip 15.5.5.5 name router7-1750-2 broadcast 8358662
>> dialer map ip 14.40.0.7 name router7-1750-2 broadcast 8358662
>> dialer watch-group 8
>> dialer-group 1
>> isdn switch-type basic-ni
>> isdn spid1 0835866101
>> isdn spid2 0835866301
>>!
>>interface FastEthernet0
>> no ip address
>> speed auto
>>!
>>router ospf 1
>> log-adjacency-changes
>> network 14.30.0.3 0.0.0.0 area 0
>> network 14.40.0.0 0.0.0.255 area 0
>> network 14.70.0.0 0.0.0.255 area 0
>> maximum-paths 6
>>!
>>ip classless
>>no ip http server
>>!
>>access-list 101 deny ospf any any
>>access-list 101 permit ip any any
>>dialer watch-list 8 ip 15.5.5.5 255.255.255.255
>>dialer watch-list 1 ip 14.37.0.7 255.255.255.255
>>dialer-list 1 protocol ip list 101
>>alias exec c conf t
>>alias exec rb show run | begin
>>alias exec ri show run | include
>>!
>>line con 0
>> exec-timeout 120 0
>> logging synchronous
>> login local
>>line aux 0
>>line vty 0 4
>> exec-timeout 120 0
>> login local
>>!
>>end
>>
>>Called router:
>>
>>router7-1750-2#sh ver
>>Cisco Internetwork Operating System Software
>>IOS (tm) C1700 Software (C1700-BNO3R2SV3Y56I-M), Version 12.1(17),
>>RELEASE SOFTWARE (fc1)
>>Copyright (c) 1986-2002 by cisco Systems, Inc.
>>
>>router7-1750-2#sh ru
>>Building configuration...
>>
>>Current configuration : 1794 bytes
>>!
>>version 12.1
>>no service single-slot-reload-enable
>>service timestamps debug uptime
>>service timestamps log uptime
>>no service password-encryption
>>!
>>hostname router7-1750-2
>>!
>>!
>>username zz privilege 15 nopassword
>>username router4-1750-1 password 0 ipexpert
>>!
>>!
>>!
>>!
>>memory-size iomem 25
>>ip subnet-zero
>>no ip domain-lookup
>>!
>>ip audit notify log
>>ip audit po max-events 100
>>ip multicast-routing
>>isdn switch-type basic-ni
>>!
>>!
>>!
>>!
>>voice-port 2/0
>>!
>>voice-port 2/1
>>!
>>!
>>!
>>!
>>interface Loopback0
>> ip address 14.37.0.7 255.255.255.255
>> ip ospf network point-to-point
>>!
>>interface Loopback1
>> no ip address
>>!
>>interface Loopback2
>> ip address 15.5.5.5 255.255.255.255
>>!
>>interface Serial0
>> ip address 14.70.0.7 255.255.255.0
>>!
>>interface BRI0
>> ip address 14.40.0.7 255.255.255.0
>> encapsulation ppp
>> dialer idle-timeout 0
>> dialer map ip 14.40.0.4 name router4-1750-1 broadcast
>> dialer-group 1
>> isdn switch-type basic-ni
>> isdn spid1 0835866201
>> isdn spid2 0835866401
>>!
>>interface FastEthernet0
>> no ip address
>> ip pim sparse-dense-mode
>> ip ospf message-digest-key 1 md5 ipexpert
>> ip ospf priority 0
>> ip cgmp
>> speed auto
>>!
>>router eigrp 1
>> network 14.0.0.0
>> no auto-summary
>> no eigrp log-neighbor-changes
>>!
>>router ospf 1
>> log-adjacency-changes
>> network 14.37.0.7 0.0.0.0 area 0
>> network 14.40.0.0 0.0.0.255 area 0
>> network 14.70.0.0 0.0.0.255 area 0
>> network 15.5.5.5 0.0.0.0 area 0
>> network 15.15.15.15 0.0.0.0 area 0
>> default-information originate
>>!
>>no ip classless
>>ip route 0.0.0.0 0.0.0.0 Loopback0
>>no ip http server
>>!
>>access-list 101 deny eigrp any any
>>access-list 101 permit ip any any
>>dialer-list 1 protocol ip permit
>>alias exec c conf t
>>alias exec rb show run | begin
>>alias exec ri show run | include
>>!
>>line con 0
>> exec-timeout 120 0
>> login local
>>line aux 0
>>line vty 0 4
>> exec-timeout 120 0
>> login local
>>!
>>end
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