Add Virtual IP Equivalent Source Address

1	Introduction
1.1	Prerequisites
2	Procedure

1 Introduction

This document describes how to add a Virtual IP (VIP) equivalent source address to an Abstract Load Balancer (ALB) with an existing single VIP address.

The purpose is to increase the capacity for outgoing connections, which is limited by the amount of free TCP or UDP ephemeral port numbers available to an IP address.

After the procedure is completed, if all ephemeral port numbers for any VIP address in the ALB are consumed for outgoing traffic, more outgoing connections can still be made, but with the added address used as source IP address. Thus, the capacity ceiling is raised for outgoing connections.

For TCP and UDP traffic, the routing in the external network with respect to VIP addresses is not arranged for "shared fate paths diversity", where packets with different VIP addresses are routed with different preferences with respect to path. As from the ALB, this VIP equivalent source address can replace any other configured VIP address as a source IP address.

When the Open Shortest Path First (OSPF) routing is used to the CPE, the new VIP address is automatically announced to the CPE and thus ready for service.

1.1 Prerequisites

This section describes the prerequisites, which must be fulfilled before using the procedure.

1.1.1 Conditions

The following conditions must apply:

The new IP address used for the new VIP equivalent source address is a routable IP address, selected in accordance with the address plan of the external network.
The ALB is known.
When static routing is used to connect to the Customer-Premises Equipment (CPE), for example, external routers, the CPE is reconfigured for the new IP address.
It is verified that in the External Network, policy-based routing, based on VIP address as source IP address for traffic separation purposes is not required.
An Ericsson Command-Line Interface (ECLI) session in Exec mode is in progress.

2 Procedure

To add a VIP equivalent source address:

Navigate to the EvipVips Managed Object (MO), for example:
>dn ManagedElement=NODE06ST,Transport=1,Evip=1,EvipAlbs=1,EvipAlb=NetworkPartnerVPN_01,EvipVips=1
Enter Config mode:
(EvipVips=1)>configure
Set the new VIP equivalent source address, for example:
(config-EvipVips=1)>EvipVip=10.1.1.7
Allow the new VIP address to be used for an alias IP address for outgoing connections:
(config-EvipVip=10.1.1.7)>equivSrcAddr="yes"
Commit the settings:
(config-EvipVip=10.1.1.7)>commit
Navigate to the EvipVips MO:
(EvipVip=10.1.1.7)>up

Verify the settings:

(EvipVips=1)>show -r

The following is an example output:

EvipVips=1
   EvipVip=10.1.1.1
      equivSrcAddr="no"
   EvipVip=10.1.1.7
      equivSrcAddr="yes"