Two remote site at a different locations havong a same subnet

[hakimkipli]

Hi,

I still confused on how to implement this. Currently, we have to remote site having a same subnet 192.168.1.x/24. Both sites using the same subnet and we need to connect to this site. Both site will terminated at our CE router in their country. From my site, our CE to their CE routed via BGP using same ISP. 

SITE A : 192.168.1.0/24

SITE B : 192.168.1.0/24

we need to connect to both sites from our HQ office here. Can this be done?

[Simon.Clayton]

Good morning,

You can't advertise two identical subnets onto the same common network, you'll cause yourself a world of pain. There are two options:

1. Re-IP one of the sites to remove the conflict or;
2. You could look to NAT one of the subnets to an alternative IP address range.

Cisco have written a handy document that will help you if you look to attack this issues with option 2. The link is below:

https://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/13774-3.html

Thanks

Simon

[hakimkipli]

Hi Simon,

Thanks for the very helpfull information. Our customer is on production for more than ten years and now they have to connect to our office in Kuala Lumpur.

I've been thinking about one-to-one NAT and also parent & child VRF which I think is quite complicated. Since the connection to our office is via mpls, VRF might be the best way to solved this.

Regards,

Hakim Kipli

[Joseph W. Doherty]

You need to tie the sites together using L2. (NB: there are some technologies which allow L2 across L3.)

[hakimkipli]

Hi Jason,

Thanks for the information. Technically, how this can be done based on your suggestion. Your idea would help me a lot in this implementation. 

Thanks

HAKIM KIPLI

[Joseph W. Doherty]

"Hi Jason,"

Were you directing this question to me?

If so, technologies like L2TPv3.