Large Communication Service Providers (CSPs) that provide transit to their customers need to pay special attention to those network segments to ensure that the IPs associated to them are actually being used. What happens should that customer move on or require more (or less) IP real estate? What do communication and management processes look like to ensure that all the various departments are aligned for rapid and seamless network configuration changes with no downtime? These are issues that you should rely on your IPAM solution to resolve; otherwise, what good is it?

When providing transit, typically the customer is provided the physical connection, the other side of the p2p link between the provider edge (PE) router device and the customer edge (CE) router device, and the subnet information for the IP range that they have purchased to use. It is then up to the customer to ensure that they use that IP range correctly. As static configurations are a thing of the past, these IP subnet details are handled and communicated by announcements such as Routing Information Protocol (RIP), Border Gateway Protocol (BGP), and Open Shortest Path First (OSPF), from the customer edge device into the CSP network and aggregated accordingly at the various external peering points.

In order to make sure that the customer is using what they are supposed to—what they have paid for—you need to monitor what is happening beyond the edge; what is being published into the core network. This is where an IPAM system that can automatically analyze the network configurations coming from the CE devices to ensure compliance will save time.

There are three ways that this happens:

• Troubleshooting – Helping a customer deal with connectivity issues used to require a network engineer to log into the PE device to check configurations. A worthwhile IPAM system will have all this information and also be able to show it to a help-desk CSR, before escalating to net-ops.
• Verification – An IPAM system should automatically and reliably determine that the information provided to the customer is what has been configured on the network and continually verify to detect any changes.
• Configuration Errors – A reclaimed IP subnet can still remain active on the network while the customer moves to their new IP range. Their original range should not be re-deployed until it is removed and verified by an automated IPAM solution. Failure to do so will result in IP conflicts that will result in customer downtime.

Having an IPAM system that can provide this information automatically will cut down on OPEX by both detecting problems earlier to drastically reduce downtime, and empower the IPAM user by having this information at their fingertips.