Azure Vmx peering

[robfromsc]

I'm having an issue and need some advice.

-Azure Vmx is located in subnet A in  Vnet 1 

-Azure Vm's located  in subnet B in Vnet 1 can communicate with remote Mx clients outside of Azure

-Azure Vm's located in Vnet 2 subnet A has been peered to Vnet 1. Vm's in Vnet 1 and Vnet 2 can communicate (inside Azure). 

Issue: 

-Azure Vm's located in Vnet2 can't communicate with remote mx's and devices outside of Azure.   The issue seems to be  Vm's located in the peered Vnet2  isn't showing up as a client device on the VMX.  Is this by design or am I missing a step? 

[Pugmiester · Accepted solution]

We have a similar setup with a single Azure subscription hosting a vMX with other subscriptions peered in. Apologise if I'm already talking about things you've done but we had 2 things we didn't spot when we started to move traffic over to this setup

1. Do you have a route table in VNET 2 pointing to the LAN IP of the vMX in VNET 1? Azure takes care of getting traffic between the VNET's but the route table gets traffic to anything outside Azure

2. Did you add the VNET 2 subnet as a local subnet on the vMX

[robfromsc]

It was a layer 8 issue (my fault) .  I had the local lan advertisement as a /21 but the new subnet was encompassed with the /21.  I appreciate your assistance. 

[Pugmiester]

No problem. It's usually me asking for help so it makes a change when I spot a question I might be able to answer before the experts beat me to it 🙂

"layer 8", I love that

[DurgaPrasad_DP]

Hi,

Did you have in place as suggested by Pugmeister -

1. A route table in VNET 2 pointing to the LAN IP of the vMX in VNET 1? Azure takes care of getting traffic between the VNET's but the route table gets traffic to anything outside Azure

2. Did you add the VNET 2 subnet as a local subnet on the vMX

in addition to your Layer 8 issue 🙂 ?

Thanks/DP