Route maps on Expressroute

Question

I have a virtual HUB in vWAN which has a Expressroute connection to DC and SDWAN cEDGEs that provide access from all branches to VNETs. I would like to use route maps on Expressroute to advertise to DC VNET prefix 10.193.0.0/24, 10.193.2.0/24 and supress all other prefixes. I created route map with following rules however all routes get suppressed.

Rule name: Allow Expressroute prefixes

Property: Route Prefix

Criterion: Equals

Value: 10.193.0.0/24, 10.193.2.0/24

Action: Modify

Property:

Action:

Value:

Next step: Continue

Rule name: Deny Any

Property:

Criterion:

Value:

Action: Drop

Property:

Action:

Value:

Next step: Terminate

Answer 1

@Aleksandar Nikolovski ,

I believe you are aware that Route-maps is currently in Public Preview and is provided without a service-level agreement. Route-maps shouldn't be used for production workloads.

Please make sure you are testing the above in a Test environment,

With that said,

• From your verbatim, I believe you would like to advertise only 10.193.0.0/24, 10.193.2.0/24 (Spoke VNET Ranges) to the DCs connected to ExR and drop everything else
• Please correct me if I am wrong.

Can you please interpret the above rules, on how you believe they process.

• I think the second rule, is getting processed on the first rule once again.
• So the modifications done by first rule, is over written by second rule and everything is dropped.

What I propose is,

#Rule1

• Use only one rule, so Next Step is "Terminate"
• For Match, do not specify any match condition
  • This will make sure all routes from the applied connection will be matched
• Then for Actions,
  • I see you are expected to select either Drop or Modify and we cannot leave this blank
  • So, select Modify and
    • Property : Route Prefix
    • Action : Replace
    • Value : 10.193.0.0/24, 10.193.2.0/24
• And then apply the RouteMap to Outbound Route-map of ExR

In essence, we are matching everything and replacing it with 10.193.0.0/24, 10.193.2.0/24 for advertisement.

Once done, please validate the routes being advertised using the Route Map dashboard (Preview).

Refer: What are route-map rules?

Hope this helps. Once again, as this feature is in preview, please make sure you test this in a Test/Dev Environment.

Thanks,

Kapil

---

Please Accept an answer if correct.

Original posters help the community find answers faster by identifying the correct answer.