From: OhioHondo (ohiohondo@columbus.rr.com)
Date: Thu Mar 20 2003 - 11:43:14 GMT-3
Hunt
The Virtual Link statement uses OSPF Router-ID's, not IP addresses.
Router's R1 and R2 have to make an OSPF neighbor adjacency for area 2 over
VLAN 30 before the Virtual Link will work. If this adjacency is made, Router
1 will see it has an OSPF adjacency with OSPF router-id 200.200.200.1.
Router 2 will see it has an OSPF neighbor adjacency with OSPF router-id
11.1.1.1. That's all they need to know to establish the virtual link. Router
1 has OSPF Area 11. Router 2 needs to have a presence of OSPF area 0. (Which
they both do.)
You do not need the default route to establish this virtual link.
If you're troubleshooting, make sure that you have the Area 2 OSPF neighbor
adjacency and that the routers are reporting the router-id's that you
expect.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Hunt Lee
Sent: Thursday, March 20, 2003 8:17 AM
To: ccielab@groupstudy.com
Subject: Trunk mystery
Hi group,
I'm confused on the following eg.
<--- Area 2 ----->
Trunk VLAN30
11.1.1.1---R1 --- Cat 3550 ---- R2---200.200.200.1
(Area 11) |
|
|
other OSPF routers (OSPF Area 0)
R2 is advertising a default route out to OSPF
by: ip route 0.0.0.0 0.0.0.0 137.20.20.2
Both 11.1.1.1 & 200.200.200.1 are Loopback interface by R1 and R2
respectively
I scratched my head as to how can R2 establish a virtual-link to R1 with IP
11.1.1.1, where 11.1.1.1 is in Area 11, since I was expecting that R2 won't
be able
to know about 11.1.1.1 until the Virtual-Link is formed...
At R2:-
interface Loopback0
ip address 200.200.200.1 255.255.255.0
interface Ethernet0
ip address 137.20.20.1 255.255.255.0
ip ospf priority 200
router ospf 1
router-id 200.200.200.1
log-adjacency-changes
area 2 virtual-link 11.1.1.1 <---- How can R2 see 11.1.1.1
network 137.20.20.1 0.0.0.0 area 2
network 150.100.32.2 0.0.0.0 area 0
default-information originate metric 100 metric-type 1
At R1:-
interface Loopback0
ip address 11.1.1.1 255.255.255.0
interface FastEthernet0/0.1
encapsulation dot1Q 10
ip address 192.168.1.11 255.255.255.224
!
interface FastEthernet0/0.2
encapsulation dot1Q 20
ip address 10.90.1.11 255.255.255.0
!
interface FastEthernet0/0.3
encapsulation dot1Q 30
ip address 137.20.20.11 255.255.255.0
!
router ospf 1
router-id 11.1.1.1
log-adjacency-changes
area 2 virtual-link 200.200.200.1
summary-address 192.168.1.0 255.255.255.0
network 11.1.1.1 0.0.0.0 area 11
network 137.20.20.11 0.0.0.0 area 2
And at 3550:-
interface FastEthernet0/2
description R2
switchport access vlan 30
switchport mode access
no ip address
interface FastEthernet0/14
description R1's Trunk port
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-39,184-4094
switchport mode trunk
no ip address
duplex full
speed 100
Regards,
Lee
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This archive was generated by hypermail 2.1.4 : Sat Apr 05 2003 - 08:51:42 GMT-3