centos 7 router with two same subnets?

[prologas]

Any chance to make centos 7 router reach two same subnets 10.10.10.0/24? I think some kind of IP forwarding?

For example: 172.16.16.10 > 10.10.10.10 // 172.15.15.10 > 10.10.10.10
Here can't be any VLAN or diff subnet. Just some kind of resolving IP not from origin.

Thanks!

[jlehtone]

"two same subnets"?

Do you mean that the router is directly connected to subnet 10.10.10.0/24 and to subnet 10.10.10.0/24?
Then you ask how to ensure that traffic destined to 10.10.10.10 will go to 10.10.10.10 and not to 10.10.10.10, because the 10.10.10.10 and the 10.10.10.10 are two separate and unique machines?


That sounds a bit confusing. There is some support for network namespaces. Never used them, but they look like an option.

[prologas]

Yeah, sounds ridiculous, but it has to be done somehow. Look it from this point that router has ipSec tunnel to subnet 10.10.10.0/24, but at local point we have same 10.10.10.0/24.

[TrevorH]

You can't do that. One side has to change.

[jlehtone]

Ok, lets invent names:
Subnet Local10 has 10.10.10.0/24 and is link-local
Subnet Remote has 10.10.10.0/24 and is tunnel

Subnet Local15 has 172.15.15.0/24 and is link-local?
Subnet Local16 has 172.16.16.0/24 and is link-local?
(How many physical NIC's on the router?)

What are the allowed routes?
Local10 <--> Local15 ?
Local16 <--> Remote ?
Local10 <--> Remote ?
Local15 <--> Local16 ?
?


Edit: @Trevor: While seemingly impossible, it might still be doable to some extent. (Doable != sane.)

[prologas]

That's looks something. Router has 8 NIC's. 4 PCIexpress + 4 inbound. What about technology from openstack with floating ips?

[jlehtone]

Okay, there is some hardware. That, however, is not the main issue.

How many link-local networks are there? 4?
Which networks must be able to communicate with each other?
We need a complete list of rules that need to be implemented.