From: Rory Grant (Rory.Grant@telindus.co.uk)
Date: Sat Nov 17 2007 - 13:31:25 ART
Hi there,
The problem was that I was using a x-over HWIC to WIC serial cable between these two routers and for some reason R5 was setting an interface BW of 128K for all attached serial interfaces instead of 1544 Kb. This is a c2811 router running "flash:c2800nm-adventerprisek9-mz.124-15.T1.bin".
Any suggestions why this is doing this???? Many thanks.
Rory Grant
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Rory Grant
Sent: Saturday, November 17, 2007 2:46 PM
To: 'ccielab@groupstudy.com'
Cc: mark hodgetts
Subject: IE lab 3 - auto-cost reference-bandwidth 20000 kills my routes learned from R4 and will not pass them on to other OSPF speaking routers - Can you spot anything obvious???
Hi there,
I am a little confused as to why this is happening. Below is the output from
R4 and R5 which are connected by a FR connection (136.1.245.0/24) and backup
PPP serial connection (136.1.45.0/24). We also have a virtual-link running
over the PPP connection between these routers. The task specifies that you
need to prefer the connection over the FR so the cost is increased over the
PPP connection to achieve this. Up till now all is well and you can see the
first 2 outputs which show that everything is fine.
Rack1R4#sho ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs
F/C
Lo0 1 0 150.1.4.4/24 1 P2P
0/0
Se0/0/0 1 0 136.1.245.4/24 64 P2MP
1/1
VL0 1 0 136.1.45.4/24 65534 P2P
1/1
Fa0/1 1 4 136.1.4.4/24 1 DR
0/0
Fa0/0 1 44 136.1.44.4/24 1 DR
0/0
Se0/1/0 1 45 136.1.45.4/24 65534 P2P
1/1
Rack1R5#sh ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs
F/C
Lo0 1 0 150.1.5.5/24 1 P2P
0/0
Se0/0/0.245 1 0 136.1.245.5/24 781 P2MP
2/2
Se0/0/0.15 1 0 136.1.15.5/24 781 P2P
1/1
VL0 1 0 136.1.45.5/24 65534 P2P
1/1
Se0/0/1 1 45 136.1.45.5/24 65534 P2P
1/1
Rack1R4#sh ip ospf neig
Neighbor ID Pri State Dead Time Address
Interface
150.1.5.5 0 FULL/ - 00:01:52 136.1.245.5
Serial0/0/0
150.1.5.5 0 FULL/ - - 136.1.45.5
OSPF_VL0
150.1.5.5 0 FULL/ - 00:00:32 136.1.45.5
Serial0/1/0
Rack1R5#sho ip ospf neig
Neighbor ID Pri State Dead Time Address
Interface
150.1.4.4 0 FULL/ - 00:01:58 136.1.245.4
Serial0/0/0.245
150.1.2.2 0 FULL/ - 00:01:39 136.1.245.2
Serial0/0/0.245
150.1.1.1 0 FULL/ - 00:00:37 136.1.15.1
Serial0/0/0.15
150.1.4.4 0 FULL/ - - 136.1.45.4
OSPF_VL0
150.1.4.4 0 FULL/ - 00:00:36 136.1.45.4
Serial0/0/1
Rack1R5#pi 150.1.4.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 150.1.4.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/60 ms
Next we have to set the Reference-bandwidth to 20000 on all OSPF routers and
this is when strange things happen...
Rack1R4(config-router)#do sho ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs
F/C
Lo0 1 0 150.1.4.4/24 1 P2P
0/0
Se0/0/0 1 0 136.1.245.4/24 12953 P2MP
1/1
VL0 1 0 136.1.45.4/24 65534 P2P
1/1
Fa0/1 1 4 136.1.4.4/24 200 DR
0/0
Fa0/0 1 44 136.1.44.4/24 200 DR 0/0
Se0/1/0 1 45 136.1.45.4/24 65534 P2P 1/1
Rack1R5(config-router)#auto-cost reference-bandwidth 20000 (this is done on
routers R1; R2; R4 and R5)
% OSPF: Reference bandwidth is changed.
Please ensure reference bandwidth is consistent across all routers.
Rack1R5(config-router)#do sho ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs
F/C
Lo0 1 0 150.1.5.5/24 1
P2P 0/0
Se0/0/0.245 1 0 136.1.245.5/24 65535 P2MP
2/2
Se0/0/0.15 1 0 136.1.15.5/24 65535 P2P
1/1
VL0 1 0 136.1.45.5/24 65534 P2P
1/1
Se0/0/1 1 45 136.1.45.5/24 65534 P2P
1/1
Rack1R5(config-router)#do sho ip route 150.1.4.4
% Subnet not in table
When I do a 'debug ip routing' on R5 and clear the ip ospf process on R5 it
learns all the prefixes from R4 and then immediatly drops them from the ip
forwarding/routing table. R5 correctly redistributes these prefixes to SW1
(RIP domain with distance 109) and SW1 can ping prefixes attached to R4,
however these R4 prefixes from R5 do not get passed onto the other Area 0 OSPF
routers (R1 and R2). Another weird thing is that R5's virtual link goes down
but R4's side remains up.
Rack1R5#
*Nov 17 14:56:25.951: RT: del 136.1.245.4/32 via 136.1.245.4, ospf metric
[110/65535]
*Nov 17 14:56:25.951: RT: delete subnet route to 136.1.245.4/32
*Nov 17 14:56:25.951: RT: NET-RED 136.1.245.4/32
*Nov 17 14:56:25.951: RT: del 150.1.4.0/24 via 136.1.245.4, ospf metric
[110/65536]
*Nov 17 14:56:25.951: RT: delete subnet route to 150.1.4.0/24
*Nov 17 14:56:25.951: RT: NET-RED 150.1.4.0/24
*Nov 17 14:56:25.951: RT: del 136.1.4.0/24 via 136.1.245.4, ospf metric
[110/65735]
*Nov 17 14:56:25.955: RT: delete subnet route to 136.1.4.0/24
*Nov 17 14:56:25.955: RT: NET-RED 136.1.4.0/24
*Nov 17 14:56:25.955: RT: del 136.1.44.0/24 via 136.1.245.4, ospf metric
[110/65735]
Rack1R5#
*Nov 17 14:56:25.955: RT: delete subnet route to 136.1.44.0/24
*Nov 17 14:56:25.955: RT: NET-RED 136.1.44.0/24
Interestingly it does not learn or remove the PPP /32 route for the R4 end.
If I remove the auto-cost reference-bandwidth 20000 statement then everything
works as it should.
Below is the config without ref-bw statements when everything works...
R4:
interface Loopback0
ip address 150.1.4.4 255.255.255.0
ip ospf network point-to-point
!
interface FastEthernet0/0
ip address 136.1.44.4 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 136.1.4.4 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0/0
ip address 136.1.245.4 255.255.255.0
encapsulation frame-relay
ip ospf message-digest-key 1 md5 CISCO
ip ospf network point-to-multipoint
frame-relay map ip 136.1.245.5 405 broadcast
no frame-relay inverse-arp
!
interface Serial0/1/0
ip address 136.1.45.4 255.255.255.0
encapsulation ppp
ip ospf network point-to-point
ip ospf cost 65534
clock rate 64000
ppp authentication pap
ppp pap sent-username Rack1R4 password 0 CISCO
!
router ospf 1
router-id 150.1.4.4
log-adjacency-changes
area 0 authentication message-digest
area 45 virtual-link 150.1.5.5 message-digest-key 1 md5 CISCO
network 136.1.4.4 0.0.0.0 area 4
network 136.1.44.4 0.0.0.0 area 44
network 136.1.45.4 0.0.0.0 area 45
network 136.1.245.4 0.0.0.0 area 0
network 150.1.4.4 0.0.0.0 area 0
R5:
interface Loopback0
ip address 150.1.5.5 255.255.255.0
ip ospf network point-to-point
!
interface Serial0/0/0.15 point-to-point
ip address 136.1.15.5 255.255.255.0
ip ospf message-digest-key 1 md5 CISCO
frame-relay interface-dlci 501
!
interface Serial0/0/0.245 multipoint
ip address 136.1.245.5 255.255.255.0
ip ospf message-digest-key 1 md5 CISCO
ip ospf network point-to-multipoint
frame-relay map ip 136.1.245.2 502 broadcast
frame-relay map ip 136.1.245.4 504 broadcast
no frame-relay inverse-arp
!
interface Serial0/0/1
ip address 136.1.45.5 255.255.255.0
encapsulation ppp
ip ospf network point-to-point
ip ospf cost 65534
ppp authentication pap
ppp pap sent-username Rack1R5 password 0 CISCO
!
router ospf 1
router-id 150.1.5.5
log-adjacency-changes
area 0 authentication message-digest
area 45 virtual-link 150.1.4.4 message-digest-key 1 md5 CISCO
redistribute rip subnets
network 136.1.15.5 0.0.0.0 area 0
network 136.1.45.5 0.0.0.0 area 45
network 136.1.245.5 0.0.0.0 area 0
network 150.1.5.5 0.0.0.0 area 0
!
router rip
version 2
redistribute ospf 1 metric 1
passive-interface default
no passive-interface FastEthernet0/0
no passive-interface FastEthernet0/1
network 136.1.0.0
network 192.10.1.0
distance 109
no auto-summary
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:30 ART