12-11-2022 05:35 AM - edited 12-11-2022 05:36 AM
Hello,
I am struggling to configure the Topology attached bellow and I struggle to obtain full connectivity, to be more exact, I have encountered a behavior, where:
R3 Routing table does not include route to 1.1.1.1/32
R2 Routing table does not include route to 3.3.3.3/32
R1 Routing table does not include a route to 2.2.2.2/32
In other words:
R1 does not have any connectivity to Area 2
R2 does not have any connectivity to Area 3
R3 does not have any connectivity to Area 1
I want to configure it so that full connectivity would be present, that means I could access (ping) each IP address from any point on the network. I feel like I am missing something really important here, Could someone please advise?
NOTE: R1 loopback - Area 1, R2 loopback -Area 2, R3 loopback - Area 3
My configuration:
R1:
R2:
R3:
12-11-2022 05:41 AM
Hello
configure the link between r1/r2 to be in area 0
12-11-2022 05:48 AM - edited 12-11-2022 06:30 AM
Thanks Paul,
This did help, I reconfigured Area 1 -> Area 0, Area 2 -> Area 1 and Area 3 -> Area 2
12-11-2022 05:51 AM
this will not work optimal but I have workaround for you
config Lo in each three router
config this Lo to be in area 0
this will make ABR advertise L3 to other area even if there is no real Area 0 in your topology.
friend this workaround, try config Area 0 in real network
12-11-2022 02:30 PM
Yup, as expected.
"I feel like I am missing something really important here, Could someone please advise?"
Correct, you are missing something really important.
An OSPF router will "know" of an area's topology which its has a "foot" in that area. But for router's to exchange routes, between areas, which they do not connect to, you need an area zero.
What @MHM Cisco World suggested, I believe will work (as might just doing what he suggested on any two of the three routers).
What's also to be understood, what @MHM Cisco World suggested, and what he notes, this is a "workaround", i.e. not, shall we say, a "best practice" for real networks.
12-12-2022 08:38 AM
BTW, reason I mention what @MHM Cisco World proposed would NOT be best practice, it creates a partitioned area zero, a "bad thing", but for your posted topology, would still work, I believe.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide