Load balancing service is not working when configured on an additional public NIC in VPC Virtual Router

Problem

 

Load balancing service is not working when configured on an additional public NIC in VPC Virtual Router

Steps to Reproduce the problem

1. Deploy two VMs in a VPC tier

2. Acquire an public IP from a new subnet in the VPC

3. Configure LB port 80 to two VMS on the additional IP.

  1. Try accessing the service through the load balancing IP and it won't be accessible.

Root Cause

When a user acquires a new public IP and if it happens to acquire them from a different subnet than the one already in use, a new NIC is plugged in to the VPC virtual router and additional policy routing is configured to ensure the routing. In this case ip rules are missing to route the traffic properly on the correct interface.

Due to this the LB traffic from the guest vm is passing through the default source nat interface. This resulted resulting incorrect packet forwarding and effectively blocking access the load balanced servers.

Required Modification

Added ip routes and rules to route the traffic on the correct interface.

Reason for Modification

User should be able to configure and use load balancing service in any public IP in the network having load balancing service enabled.

 

Resolution/Workaround

Add  ip routes and rules to route the traffic on the correct interface.

Verification

Acquire public ip from the additional public subnet.

2. Configure the LB rule on it and send the traffic from the public side.

3. Capture the traffic on the additional public subnet interface. Incoming and outgoing of LB traffic should pass through the additional public subnet interface.

4. Capture the traffic on source nat interface. The LB traffic should not pass through it.

Impact on Existing System

 

Load balancing service would be available through additional public NIC of VPC virtual router as well.

Potential Adverse Effect

 

There is no known adverse effect on the system

Document ID:
214443486

Product:
CloudPlatform

Version:
4.2.1-6

Reference Jira ID:
CS-47253

 
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