2 Same IP can passes traffic form one IPSEC tunnel

[Nehpalrathore]

Hi,

I have one IPSEC tunnel to monitor customer end network devices. Now this customer at his backend have multiple private IP subnets and out of them some are overlap with each other. 

Now customer need to monitor all network devices through one IP sec tunnel. 

So my question is, It is possible to pass traffic of 2 same private IP from one IPSEC tunnel?

If yes then please guide me the solution.

Thanks.

[srajeswaran]

There is no issue in sending traffic to same private IPs, the issue is how the gateway will decide on which destination to use.

On the local LAN with overlapping subnets, how is the connection works now, these don't talk each other?

They need to implement Source NAT for one of the overlapping subnets

[Nehpalrathore]

On the local LAN with overlapping subnets, how is the connection works now?

-- This i need to check with customer.

They need to implement Source NAT for one of the overlapping subnets

-- Customer having Cisco ASA firewall as gateway so SNAT will be configured on this device correct.

Can you elaborate bit more how SNAT will configure. Is many-to-one or ont-to-one

Fortigate Firewall (Myside) ======== IPSEC tunnel ========== Cisco ASA Firewall (Customer end)

[srajeswaran]

I believe there is some other L3 device after Cisco ASA which is separating the overlapping subnet. We may need to do the NAT on that.
It will be better to confirm the NAT options after understanding how it works currently with overlapping subnets. We need to configure according to the current connectivity.