03-02-2011 04:06 AM - edited 03-06-2019 03:51 PM
I have two 2911 routers and one 2901 router running OSPF between them.
Router 1.1.1.1 is connected to router 2.2.2.2 via G0/1
Router 1.1.1.1 is connected ro router 3.3.3.3 via G0/2
As you can see from the snippets below all the neighbors come up as full and two routers get the routes from the router in the middle (1.1.1.1), however the middle one is not picking up any routes. Everything else is set to default. Any ideas as to what is going on here?
Configuration for Router 1.1.1.1
router ospf 1
router-id 1.1.1.1
network 10.10.1.0 0.0.0.255 area 0
network 10.100.1.0 0.0.0.255 area 0
network 128.11.0.0 0.0.255.255 area 0
network 192.168.17.0 0.0.0.3 area 0
network 192.168.17.8 0.0.0.3 area 0
Neighbors for Router 1.1.1.1
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 1 FULL/DR 00:00:39 192.168.17.10 GigabitEtherne
t0/2
2.2.2.2 1 FULL/DR 00:00:34 192.168.17.2 GigabitEtherne
t0/1
Database for 1.1.1.1
OSPF Router with ID (1.1.1.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 1247 0x80000006 0x003837 4
2.2.2.2 2.2.2.2 1253 0x80000061 0x00F4D4 1
3.3.3.3 3.3.3.3 1248 0x8000005C 0x007343 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
192.168.17.2 2.2.2.2 1248 0x80000050 0x00A7B5
192.168.17.10 3.3.3.3 1243 0x80000052 0x0057F3
Route table for Router 1.1.1.1
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback1
10.0.0.0/8 is variably subnetted, 8 subnets, 3 masks
C 10.10.1.0/24 is directly connected, GigabitEthernet0/0.10
L 10.10.1.1/32 is directly connected, GigabitEthernet0/0.10
C 10.10.10.0/29 is directly connected, GigabitEthernet0/0
L 10.10.10.1/32 is directly connected, GigabitEthernet0/0
C 10.100.1.0/24 is directly connected, GigabitEthernet0/0.100
L 10.100.1.1/32 is directly connected, GigabitEthernet0/0.100
C 10.200.1.0/24 is directly connected, GigabitEthernet0/0.200
L 10.200.1.1/32 is directly connected, GigabitEthernet0/0.200
192.68.117.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.68.117.0/24 is directly connected, GigabitEthernet0/0.117
L 192.68.117.1/32 is directly connected, GigabitEthernet0/0.117
192.168.17.0/24 is variably subnetted, 4 subnets, 2 masks
C 192.168.17.0/30 is directly connected, GigabitEthernet0/1
L 192.168.17.1/32 is directly connected, GigabitEthernet0/1
C 192.168.17.8/30 is directly connected, GigabitEthernet0/2
L 192.168.17.9/32 is directly connected, GigabitEthernet0/2
Configuration for 2.2.2.2
router ospf 1
router-id 2.2.2.2
network 10.10.2.0 0.0.0.255 area 0
network 10.100.2.0 0.0.0.255 area 0
network 192.168.17.0 0.0.0.3 area 0
Neighbors for Router 2.2.2.2
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:00:35 192.168.17.1 GigabitEtherne
t0/1
Dtabase for Router 2.2.2.2
OSPF Router with ID (2.2.2.2) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 1528 0x80000006 0x003837 4
2.2.2.2 2.2.2.2 1533 0x80000061 0x00F4D4 1
3.3.3.3 3.3.3.3 1528 0x8000005C 0x007343 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
192.168.17.2 2.2.2.2 1528 0x80000050 0x00A7B5
192.168.17.10 3.3.3.3 1525 0x80000052 0x0057F3
Route Table for Router 2.2.2.2
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback1
10.0.0.0/24 is subnetted, 2 subnets
O 10.10.1.0 [110/2] via 192.168.17.1, 00:26:37, GigabitEthernet0/1
O 10.100.1.0 [110/2] via 192.168.17.1, 00:26:37, GigabitEthernet0/1
192.168.17.0/24 is variably subnetted, 3 subnets, 2 masks
C 192.168.17.0/30 is directly connected, GigabitEthernet0/1
L 192.168.17.2/32 is directly connected, GigabitEthernet0/1
O 192.168.17.8/30
[110/2] via 192.168.17.1, 00:26:27, GigabitEthernet0/1
Configuration for Router 3.3.3.3
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 10.100.3.0 0.0.0.255 area 0
network 10.200.3.0 0.0.0.255 area 0
network 192.168.17.8 0.0.0.3 area 0
Neighbors for Router 3.3.3.3
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:00:35 192.168.17.9 GigabitEtherne
t0/1
Database for Router 3.3.3.3
OSPF Router with ID (3.3.3.3) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 1854 0x80000006 0x003837 4
2.2.2.2 2.2.2.2 1860 0x80000061 0x00F4D4 1
3.3.3.3 3.3.3.3 1853 0x8000005C 0x007343 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
192.168.17.2 2.2.2.2 1855 0x80000050 0x00A7B5
192.168.17.10 3.3.3.3 1849 0x80000052 0x0057F3
Route Table for Routerr 3.3.3.3
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.33 is directly connected, Loopback1
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
O 10.10.1.0/24 [110/2] via 192.168.17.9, 00:31:29, GigabitEthernet0/1
C 10.10.3.0/24 is directly connected, GigabitEthernet0/0.10
L 10.10.3.1/32 is directly connected, GigabitEthernet0/0.10
O 10.100.1.0/24 [110/2] via 192.168.17.9, 00:31:29, GigabitEthernet0/1
192.168.17.0/24 is variably subnetted, 3 subnets, 2 masks
O 192.168.17.0/30
[110/2] via 192.168.17.9, 00:31:29, GigabitEthernet0/1
C 192.168.17.8/30 is directly connected, GigabitEthernet0/1
L 192.168.17.10/32 is directly connected, GigabitEthernet0/1
Solved! Go to Solution.
03-07-2011 05:02 AM
Thats because when you redistribute they will be external. If you don't want this, and what I can see from your config, you need to advertise the networks. You seem to be missing some but I don't know if that is by design / your requirements.
Remeber in OPSF your network commands really just tell the router which interfaces will participate in OSPF and the networks you want to advertise. You only need to "speak" OSPF on those interfaces directly involved in establishing neigbor relationships and so I would add the passive default command. I used GNS3 to make my lab so my interfaces are different to your, but you should get the idea.
For exmaple, if you want full connectivity I would do the following (and this way you don't get external routes).
1.1.1.1
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 1.1.1.1 0.0.0.0 area 0 ----> I add this to be able to ping the loopback addresses.
network 10.10.1.0 0.0.0.255 area 0
network 10.100.1.0 0.0.0.255 area 0
network 128.11.0.0 0.0.255.255 area 0
network 192.168.17.0 0.0.0.3 area 0
network 192.168.17.8 0.0.0.3 area 0
network 10.10.10.0 0.0.0.255 area 0 ----> I add this, missing?.
passive-interface default -----> Added. I only want to advertise OSPF to my neighbors so I turn off by default on all interfaces
no passive-interface FastEthernet0/0 -----> And tun on again here on this interface
no passive-interface FastEthernet0/1 -----> And this one.
03-02-2011 04:09 AM
Make sure your router 1.1.1.1 is the DR.
Regards,
Ian
03-02-2011 04:19 AM
How can I force that?
03-02-2011 04:26 AM
ip ospf priority <0-255> under your routing process. Sorry my mistake I meant interface. It won't let you put ip ospf priority under the routing process.
you should set your spokes with priority of 0 so they don't take part in the DR/BDR election. then you can leave the 1.1.1.1 as default OR you can just put a higher priority on your 1.1.1.1 (hub) router.
you will need to restart the ospf processes so the "election" takes place again. you can use the #clear ip ospf process
but if you have the option to you can reload the routers.
don't forget after making the changes to #wr mem.
03-02-2011 04:37 AM
Hi,
To achieve what Ian said, the quickest way is to issue on R2 and R3 interfaces connected to R1 the following command:
ip ospf priority 0
Then instantaneously R1 will be the DR and the other 2 will be DROTHERS.
But there is something I'd like to know: how come in a broadcast multiaccess media the DR election went so wrong?
Can you post sh run | s ospf as well as sh ip os in br and sh run int gix/x for on the 3 routers.
Regards.
Alain.
03-02-2011 05:39 AM
Here are the requested shows. I have set the priority to 0 on 2.2.2.2 and 3.3.3.3 and have verified this with show ip os top. I have rebooted all of the routers and it sill shows BDR on these two.
1.1.1.1
NGHA-RH-RTR-01#sh run | s ospf
router ospf 1
router-id 1.1.1.1
network 10.10.1.0 0.0.0.255 area 0
network 10.100.1.0 0.0.0.255 area 0
network 128.11.0.0 0.0.255.255 area 0
network 192.168.17.0 0.0.0.3 area 0
network 192.168.17.8 0.0.0.3 area 0
NGHA-RH-RTR-01#sh ip os in br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Gi0/2 1 0 192.168.17.9/30 1 BDR 1/1
Gi0/1 1 0 192.168.17.1/30 1 BDR 1/1
Gi0/0.100 1 0 10.100.1.1/24 1 DR 0/0
Gi0/0.10 1 0 10.10.1.1/24 1 DR 0/0
NGHA-RH-RTR-01#sh run int g0/1 (to 2.2.2.2)
Building configuration...
Current configuration : 102 bytes
!
interface GigabitEthernet0/1
ip address 192.168.17.1 255.255.255.252
duplex auto
speed auto
end
GHA-RH-RTR-01#sh run int g0/2 (to 3.3.3.3)
Building configuration...
Current configuration : 137 bytes
!
interface GigabitEthernet0/2
description Link to Vulcan Street
ip address 192.168.17.9 255.255.255.252
duplex auto
speed auto
end
2.2.2.2
NGHA-BD-RTR-01#sh run | s ospf
router ospf 1
router-id 2.2.2.2
priority 0
network 10.10.2.0 0.0.0.255 area 0
network 10.100.2.0 0.0.0.255 area 0
network 192.168.17.0 0.0.0.3 area 0
NGHA-BD-RTR-01#sh ip os in br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Gi0/1 1 0 192.168.17.2/30 1 DR 1/1
Gi0/0.100 1 0 10.100.2.1/24 1 DOWN 0/0
Gi0/0.10 1 0 10.10.2.1/24 1 DOWN 0/0
NGHA-BD-RTR-01#sh run int g0/1 (to 1.1.1.1)
!
interface GigabitEthernet0/1
description Link to Reidhouse
ip address 192.168.17.2 255.255.255.252
duplex auto
speed auto
end
3.3.3.3
NGHA-VS-RTR-01#sh run | s ospf
router ospf 1
router-id 3.3.3.3
priority 0
log-adjacency-changes
network 10.100.3.0 0.0.0.255 area 0
network 10.200.3.0 0.0.0.255 area 0
network 192.168.17.8 0.0.0.3 area 0
NGHA-VS-RTR-01#sh ip os in br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Gi0/1 1 0 192.168.17.10/30 1 DR 1/1
NGHA-BD-RTR-01#sh run int g0/1 (to 1.1.1.1)
NGHA-BD-RTR-01#sh run int g0/1 (to 1.1.1.1)
interface GigabitEthernet0/1
description Link to Reidhouse
ip address 192.168.17.10 255.255.255.252
duplex auto
speed auto
03-02-2011 06:21 AM
Hi,
I have rebooted and 2.2.2.2 and 3.3.3.3 still show as BDR. I have verified with sho os top and both 2.2.2.2 and 3.3.3.3 are set to 0 andd 1.1.1.1 is set to default of 64.
the default ospf priority is 1, not 64 and when the priority is set to 0 then the router must be DROTHER for this segment and the effect is immediate,
there is no need to clear the ospf process.
2.2.2.2
NGHA-BD-RTR-01#sh run | s ospf
router ospf 1
router-id 2.2.2.2
priority 0 this must be an interface command not a routing process command and the command is ip ospf priority 0
network 10.10.2.0 0.0.0.255 area 0
network 10.100.2.0 0.0.0.255 area 0
network 192.168.17.0 0.0.0.3 area 0
I've never seen this command in router ospf process ! what version of IOS are you running? in pre-15.x this command doesn't exist and so shouldn't appear in any show command.
Regards.
Alain.
03-02-2011 04:33 AM
Hello,
Do you really need DR/BDR selection for this network type. I can see there is p2p link from 1.1.1.1 to two other
routers.
For me the routes in database and not in routing table have one solution and that is putting below two command
on all the interface enabled for ospf.
ip ospf network point-to-point
ip mtu 1500
But remember by putting command "ip ospf network point-to-point" will force ospf process to treat this ethernet link as p2p for ospf.
regards
Mahesh
03-02-2011 04:39 AM
No you don't really "need" it, but there is no harm in it if configured correctly.
03-02-2011 05:55 AM
I have added this to all of the interfaces using OSPF, cleared ip os proc and still having issue.
03-02-2011 04:40 AM
I have forced the other routers and it showws that 1.1.1.1 is the DR and the others are BDRs, but is still is not working.
03-02-2011 04:46 AM
If you put them to 0 they shouldn't be BDR they should be DROTHERS as Alain says. Given them a restart if you can.
Regards,
Ian
03-02-2011 05:42 AM
I have rebooted and 2.2.2.2 and 3.3.3.3 still show as BDR. I have verified with sho os top and both 2.2.2.2 and 3.3.3.3 are set to 0 andd 1.1.1.1 is set to default of 64.
03-02-2011 06:29 AM
Here is the show ip os top I didn't change to priority on 1.1.1.1
OSPF Router with ID (1.1.1.1) (Process ID 1)
Base Topology (MTID 0)
Topology priority is 64
Router is not originating router-LSAs with maximum metric
Number of areas transit capable is 0
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Area BACKBONE(0)
SPF algorithm last executed 00:09:51.040 ago
SPF algorithm executed 2 times
Area ranges are
OSPF Router with ID (2.2.2.2) (Process ID 1)
Base Topology (MTID 0)
Topology priority is 0
Router is not originating router-LSAs with maximum metric
Number of areas transit capable is 0
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Area BACKBONE(0)
SPF algorithm last executed 00:10:49.392 ago
SPF algorithm executed 4 times
Area ranges are
OSPF Router with ID (3.3.3.3) (Process ID 1)
Base Topology (MTID 0)
Topology priority is 0
Router is not originating router-LSAs with maximum metric
Number of areas transit capable is 0
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Area BACKBONE(0)
SPF algorithm last executed 00:12:36.696 ago
SPF algorithm executed 3 times
Area ranges are
03-02-2011 06:44 AM
Hi,
I've never seen this show command before and I don't know the meaning of this topology priority.
Can you explain what it does
UPDATE: now I know what it is but still must search what this topology priority means but I'm fairly confident that it has nothing to do with the DR election
So can you change the ospf priority under interface and tell us if it is ok now.---> sh ip os nei should show DROTHER for R2 and R3.
Regards.
Alain.
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