Routing

Hey Experts, 

A brief on my topology.

I am configuring a GRE tunnel between two routers and have established BGP. 

I have mapped the gre interface to a routing-instance.

On this routing-instance, I have created an aggregate route for one of my subnets (say 200.200.200.0/24) so that i can advertise it through BGP. 

Since the aggregate route is a reject route, what i am tryin to acheive here is to route the traffic when it comes into the tunnel interface to the master routing table where there is an matching route for this destination (200.200.200.0/23).

But as i understand, using FBF i cannot add a term saying whatever traffic comes with a destination-address of 200.200.200.0/24, go to master routing table.

set firewall family inet filter test term1 from destination-address 200.200.200.0/24 

set firewall family inet filter test term1 then routing-instance master/inet.0 ---------------i get an error saying this is           not defined

Is there any other way i can pint the traffic received on a routing-instance to master routing table??

Thanks in advance

Regards,

Varun

Hi,

you can use RIB-Group, For example

set routing-options rib-group my-gre-rib import-rib [ inet.0 vrf.inet.0 ]

then apply the RIB group (my-gre-rib) to the protocol that the main instance use to receive the prefix (i.e. under OSPF or interface routes )

and for better control you can apply import policy to the rib-group in order to import only the required prefix from main instance to the target instance,

hope it help, i u need more clarification please let me know

🙂

Hello,

If You are using "instance-type forwarding", You don't need a route to global routing table (a.k.a. inet.0)  since forwarding-instances are unidurectional and cannot have interfaces assigned into them.

If You are using "instance-type virtual-router" (VR), You could either:

1/ use RIB groups as suggested by other poster

2/ use "routing-options instance-import <import_policy_name>" in VR to inject routes into this VR from other tables including inet.0. To import routes from inet.0 into VR, use "from instance master" in import policy.

3/ have a static route as below:

set routing-instances VR1 routing-options static route <prefix/masklen> next-table inet.0

 HTH

Thanks
Alex

Hey Guys,

Appreciate your response.

My issue here is I cannot afoord to import any routes from the master into the routing-instance.

Reason being: i have a /24 aggregate route in the routing-instance and /23 direct route in the master table. If i import the /23 into the routing-instance, it would still prefer the /24 aggregate route which would black-hole the traffic since its a reject route.

Hence I am looking for options where "I DO NOT" have to import routes (using policy options/rib groups), but try and forward the traffic to the master table.

Please let me know if there is any way i can achieve this.

Let me know if you have any queries.

Thanks Again.

Regards,

Varun

Hello there,

How come Your aggregate is /24 but direct is /23?

What exactly Your aggregate is aggregating?

Of is there anything else You are not telling us about?

HTH

Thanks

Alex

Hey Alex, 

Yea. I forgot to mention that my contributing route for the aggregate route is a /32 static discard route.

The reason I do this is because I cannot further subnet my direct /23 route. And i need a /24 route when I advertise the subnet to our DDOS mitigation partners. So I have created a /24 aggregate route and added a /32 static discard to make it active.

Hope this answers your question.

Looking forward to your response.

Thanks

Varun

Just so you guys know, I did find a solution to this.

A brief on what i tested.

--------------------------------------------------------------------------------------------------------------------------------------------------------

In this, we add the gre interface to a new routing-instance.

Under the new routing-instance, I created a static route pointing to next-table inet.0

set routing-options static route 10.10.10.0/24 next-table inet.0

This route is then advertised via bgp.

Once the traffic come to the router from the tunnel, router will do a lookup on inet.0 (since "next-table inet.0" is configured under routing-instance) where it will get a valid 10.10.10.0/23 route and will forward the traffic to the destination.

And as for the outgoing traffic, it ll continue to go directly via internet, thus checking for route from master table.

This solution did fit the bill.

Hope this helps.

-Varun

Using next-table under routing-options helped.

Thanks Alex