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Announcement routes to ospf between virtual-router and default router

[ Edited ]
Wednesday

Hello!
I'm just learning and in the office I suddenly had a difficult task, which I am not ready for.
There is the following situation:
There is an office that is fully functional on the router3.
Router3 has a tunnel interface st1 to router2.
The router3 enabled the protocol ospf. The tunnel interface st1 is in area 0, and the rest of the interfaces looking towards the local network are located in area 1.

fasdfasfasdf.pngThere was a task:
Transfer users to a separate subnet.
I divided the routing tables on the router3 using the virtual-routing router instance, because otherwise, the routes go through router2, and I need to be through router1, because services for users of a separate subnet are located behind it.
In the instance router, I created a new area 2. In which I included the St2 tunnel interface to Router 1 and local interfaces.
On router 1, I created AREA 2 and turned on the St2 tunnel interface there.
But nothing works. I do not see in the new route routing table from the next area.

I'm obviously doing something wrong and I can't figure it out, for me this topic is very complex and new. How do engineers solve similar problems? I would be grateful for any help. Sorry for my English.

3 REPLIES 3
Junos

Re: Announcement routes to ospf between virtual-router and default router

Wednesday

Reading your description, this is what I am understanding: 

 

You have this topology: 

 

OSPF 1.png

But because the traffic from PCs to Services is going to R1 instead of R2, you did this:

 

OSPF 2.png 

 

  • I don't understand the area 2 including the switch and PC on the bottom right. 
  • Is R1 somehow connected to services? 
  • Are the tunnels up?
  • What kind of devices are R1, R2 and R3? 
  • Can you post the configurations of the routers? 
  • Can you post show ospf neighbors, show ospf interface from all 3 routers?  

Send more info. and I'll try to help you. Feel free to modify the diagrams and post them back.  

 

Regards,

Yasmin Lara
Sunset Learning Institute (SLI)
Juniper Ambassador #QuadE - JNCIE-SP, JNCIE-ENT, JNCIE-DC, JNCIE-SEC
JNCIS-CLOUD, JNCDS-DC, JNCIA-DevOps

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Junos

Re: Announcement routes to ospf between virtual-router and default router

Wednesday

You draw just adorable! I am even ashamed. Not very clever because of this Smiley Sad
Well, for the sake of completeness, I will try to explain how the problem appeared.

Initially, there was a topology that worked like a clock and was very logical and understandable even to me Smiley Happy
Like this:

 

OSPF 0.png

The tunnel interface st is a member of area0 and receives all routes from router2.

 

Then there was a need to create services on router1 for new individual networks on router3.

I put the switch and at the L2 level I divided one tunnel into two. Because on router 1 there are necessary services that should be available only to new subnets behind router 3.

It turned out so:

 

OSPF 1.png

I think you can guess that I began to observe the loops in the routes. Router 1 saw the network along the upper tunnel, I think because of the proximity of the route, so Ospf works, on the principle of the shortest route. However, router 3 saw some services behind router 1 through router 2 and responded to requests to it, and not to router1

 

Then I began to look for information on how to build routing correctly. I came across a virtual router and decided that it suits me. Created on router 3 virtual router and area 2. Created on router only area 2 without virtual router. I also included new interfaces with new subnets in the virtual router. It turned out something similar:

 

OSPF 2.png

There was a problem with which I came here with a question. Router 3 now has 2 routing tables. Old Inet.0 and new router-instance-name.0 

I do not know how to make routing tables accessible to each other through their tunnel interfaces, and router 2 saw area 2 only through router 1

  • I don't understand the area 2 including the switch and PC on the bottom right. 
    • This is what I want to do. The area 2 at the bottom right remained isolated.
  • Is R1 somehow connected to services?
    • Yes
  • Are the tunnels up?
    • Yes
  • What kind of devices are R1, R2 and R3?
    • R1 and R2 - SRX1500, R3 - SRX550
  • Can you post the configurations of the routers?
    • Yes, but not now, and not completely
  • Can you post show ospf neighbors, show ospf interface from all 3 routers?
    • Yes, but tomorrow

Thank you for trying to help me. I'm very bad at it Smiley Sad But I try to learn and understand how it works.

Junos

Re: Announcement routes to ospf between virtual-router and default router

Wednesday

Oh thanks! Glad you find them useful. I think we are getting somewhere. Take a look at the attached file and let me know if that helps. 

 

Regards,

Yasmin Lara
Sunset Learning Institute (SLI)
Juniper Ambassador #QuadE - JNCIE-SP, JNCIE-ENT, JNCIE-DC, JNCIE-SEC
JNCIS-CLOUD, JNCDS-DC, JNCIA-DevOps

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