01-01-2014 01:56 AM - edited 03-07-2019 05:20 PM
Hi Expert,
This is the first time I am working on OSPF and IP unnumbered interfaces.
My task is to bring-up OSPF adjacency between two CISCO-3750 switches connected back-to-back via IP unnumbered interfaces. I am using loopback interface to borrow the IP addresses for unnumbered interfaces on both the CISCO switches. After trying so many times, OSPF is not at all coming up over unnumbered interfaces though when tried with numbered interface it was fine.
I am pasting here complete running-config. Please help me in troubleshooting the issue:
Here is brief set-up info:
R1(Gi1/0/19)-------------------(Gi1/0/19)R
Swicth R1:
===========
Current configuration : 2129 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Switch
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
switch 1 provision ws-c3750g-24ts-1u
system mtu routing 1500
ip subnet-zero
ip routing
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
!
!
interface Loopback1
ip address 10.10.10.10 255.255.255.0
!
interface GigabitEthernet1/0/1
shutdown
!
interface GigabitEthernet1/0/2
shutdown
!
interface GigabitEthernet1/0/3
shutdown
!
interface GigabitEthernet1/0/4
shutdown
!
interface GigabitEthernet1/0/5
shutdown
!
interface GigabitEthernet1/0/6
shutdown
!
interface GigabitEthernet1/0/7
shutdown
!
interface GigabitEthernet1/0/8
shutdown
!
interface GigabitEthernet1/0/9
shutdown
!
interface GigabitEthernet1/0/10
shutdown
!
interface GigabitEthernet1/0/11
shutdown
!
interface GigabitEthernet1/0/12
shutdown
!
interface GigabitEthernet1/0/13
shutdown
!
interface GigabitEthernet1/0/14
shutdown
!
interface GigabitEthernet1/0/15
shutdown
!
interface GigabitEthernet1/0/16
shutdown
!
interface GigabitEthernet1/0/17
!
interface GigabitEthernet1/0/18
shutdown
!
interface GigabitEthernet1/0/19
no switchport
ip unnumbered Loopback1
ip ospf network point-to-point
!
interface GigabitEthernet1/0/20
shutdown
!
interface GigabitEthernet1/0/21
shutdown
!
interface GigabitEthernet1/0/22
shutdown
!
interface GigabitEthernet1/0/23
shutdown
!
interface GigabitEthernet1/0/24
shutdown
!
interface GigabitEthernet1/0/25
!
interface GigabitEthernet1/0/26
!
interface GigabitEthernet1/0/27
!
interface GigabitEthernet1/0/28
!
interface Vlan1
no ip address
shutdown
!
router ospf 100
router-id 100.100.100.100
log-adjacency-changes
network 10.10.10.0 0.0.0.255 area 0
!
ip classless
ip route 20.20.20.20 255.255.255.255 GigabitEthernet1/0/19
ip http server
ip http secure-server
!
!
!
control-plane
!
!
line con 0
line vty 5 15
!
!
monitor session 1 source interface Gi1/0/19
monitor session 1 destination interface Gi1/0/17
end
===
Switch#show ip interface brief | include Up
Switch#show ip interface brief | include up
GigabitEthernet1/0/17 unassigned YES unset up down
GigabitEthernet1/0/19 10.10.10.10 YES manual up up
Loopback1 10.10.10.10 YES manual up up
==================================================
Switch R2:
==================
Switch#sho run
Switch#sho running-config
Building configuration...
Current configuration : 2079 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Switch
!
boot-start-marker
boot-end-marker
!
!
!
!
no aaa new-model
switch 1 provision ws-c3750g-24t
system mtu routing 1500
authentication mac-move permit
ip subnet-zero
ip routing
!
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
!
!
interface Loopback1
ip address 20.20.20.20 255.255.255.0
!
interface GigabitEthernet1/0/1
shutdown
!
interface GigabitEthernet1/0/2
shutdown
!
interface GigabitEthernet1/0/3
shutdown
!
interface GigabitEthernet1/0/4
shutdown
!
interface GigabitEthernet1/0/5
shutdown
!
interface GigabitEthernet1/0/6
shutdown
!
interface GigabitEthernet1/0/7
shutdown
!
interface GigabitEthernet1/0/8
shutdown
!
interface GigabitEthernet1/0/9
shutdown
!
interface GigabitEthernet1/0/10
shutdown
!
interface GigabitEthernet1/0/11
shutdown
!
interface GigabitEthernet1/0/12
shutdown
!
interface GigabitEthernet1/0/13
shutdown
!
interface GigabitEthernet1/0/14
shutdown
!
interface GigabitEthernet1/0/15
shutdown
!
interface GigabitEthernet1/0/16
shutdown
!
interface GigabitEthernet1/0/17
!
interface GigabitEthernet1/0/18
shutdown
!
interface GigabitEthernet1/0/19
no switchport
ip unnumbered Loopback1
ip ospf network point-to-point
!
interface GigabitEthernet1/0/20
shutdown
!
interface GigabitEthernet1/0/21
shutdown
!
interface GigabitEthernet1/0/22
shutdown
!
interface GigabitEthernet1/0/23
shutdown
!
interface GigabitEthernet1/0/24
shutdown
!
interface Vlan1
no ip address
shutdown
!
router ospf 100
router-id 200.200.200.200
log-adjacency-changes
network 20.20.20.0 0.0.0.255 area 0
!
ip classless
ip route 10.10.10.10 255.255.255.255 GigabitEthernet1/0/19
ip http server
ip http secure-server
!
!
ip sla enable reaction-alerts
!
!
!
line con 0
line vty 5 15
!
!
monitor session 1 source interface Gi1/0/19
monitor session 1 destination interface Gi1/0/17
end
====================
Switch#sho ip interface brief | include up
GigabitEthernet1/0/17 unassigned YES unset up down
GigabitEthernet1/0/19 20.20.20.20 YES manual up up
Loopback1 20.20.20.20 YES manual up up
====================================
Thanks a lot in advance for your reply!!
Regards,
Abhi
Solved! Go to Solution.
01-01-2014 03:50 AM
Hi Abhi,
the ip unnumbered command does not work on multiaccess-interfaces like Ethernet (even when you configure it as OSPF point-to-point):
Understanding and Configuring the ip unnumbered Command
Cisco IOS IP Addressing Services Command Reference#ip unnumberd
HTH
Rolf
[EDIT]:
... apparently with the exception of high-end platforms like the 6k's:
Command History
(...)
12.2(18)SXF: This command was modified to support Ethernet physical interfaces and switched virtual interfaces (SVIs).
01-01-2014 03:50 AM
Hi Abhi,
the ip unnumbered command does not work on multiaccess-interfaces like Ethernet (even when you configure it as OSPF point-to-point):
Understanding and Configuring the ip unnumbered Command
Cisco IOS IP Addressing Services Command Reference#ip unnumberd
HTH
Rolf
[EDIT]:
... apparently with the exception of high-end platforms like the 6k's:
Command History
(...)
12.2(18)SXF: This command was modified to support Ethernet physical interfaces and switched virtual interfaces (SVIs).
01-01-2014 05:20 AM
Hi Rolf,
Thanks a lot for your reply. It was indeed very helpful.
My CISCO 3750 box has following image:
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 24 WS-C3750G-24T 12.2(52)SE C3750-IPSERVICESK9-M
So I can conclude that IP unnumbered will not be supported on this platform since it does not support serial ports.
I have CISCO 6503 box also with me.
Could you please confirm if feature would be supported on 6503 ethernet ports or not?
Regards,
Abhi
01-01-2014 05:34 AM
Hi Abhi,
you're welcome. Thanks for rating & marking as answered!
I have CISCO 6503 box also with me.
Could you please confirm if feature would be supported on 6503 ethernet ports or not?
Have a look at the Release Notes:
"New Software Features in Release 12.2(18)SXF2
...
Support with Supervisor Engine 2 for these features, which are already supported with other Supervisor Engines:
...
- IP unnumbered for VLAN-SVI interfaces
...
-VLANs over IP unnumbered sub-interfaces"
I have to say I've never done this so far on a c6500 but I think you can rely on the RN.
HTH
Rolf
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