Multi-host networking with Public and Local network cards / ips

Rancher 1.x
1

Seems like the question has been asked many times but I found no answer:

If our nodes have multiple network adapters (2 NICs), one for Public, and one for Internal / Local data exchange, ie:
Public NIC IP 215.5.5.5-215.5.5.20
Local NIC IP 172.16.130.5

What is a default Rancher / Agent behavior for scaled instances of containers, ie: Will REDIS / ELASTICSEARCH / MARIADB know about local adaptor and will utilize internal network for all data synchronization between all linked continers? Or will it work with Production NIC and essentually overload only 1 NIC and not utilize second NIC at all for any tasks, or do I need to start up Rancher Agent with some other params like CLIENT_IP to indicate that multiple NICs should be utilized, or by pointing to internal network adaptor? In which case - would it know when to change IPTABLES rules for external / internal access?

Thank you.

2

@virtuman Currently when a host is added by running the command shown in the Rancher UI, you can see that we specify the URL which has the IP address of the machine running the server. This IP address is used to establish cross host communication IPSec tunnels using swanctl/charon. So depending on which IP has been specified the NIC is picked.

In your case probably what you can do is start the rancher agents using the private IP address of the server, that way the cross host traffic is utilizing the private network and then when outside clients (public network) want to use the services they can utilize the public IP address.

3

that’s what i seemed to have been having problem with. I tried it, and everything joins to rancher correctly, but when i try to deploy an app - it never gets deployed to nodes that are added using private network ip.