How to mitigate against port exhaustion on the Kemp LoadMaster
The LoadMaster may experience port exhaustion in cases of high load when the service is non-transparent. In these cases, you can enable an option to allow for additional IP addresses to be allotted to any specific Virtual Service that expects heavy traffic.
To do this, follow the steps below in the Web User Interface (WUI):
- In the main menu, select System Configuration > Miscellaneous Options > L7 Configuration.
- Select the Allow connection scaling over 64K Connections check box.
- In the main menu, select Virtual Services and View/Modify Services.
- Click the Modify button on the relevant Virtual Service.
- Expand the Advanced Options section.
- Enter the additional addresses to allot for the Virtual Service in the Alternate Source Addresses field. In order to have an impact, you must specify at least two alternate source addresses which are space-separated.
Clients will continue to request the Virtual Service address, but connections to Real Servers will use these addresses as source addresses. Each additional address will add approximately 64,000 new available source ports for relaying client requests.
The LoadMaster will utilize these additional IP addresses in a round robin fashion when making requests to the Real Servers.