Crafting a Robust DNS Framework for Network Function Virtualization

Dilip Pillaipakkamnatt, Vice President, Service Provider Business, Infoblox

It is now widely acknowledged that Network Functions Virtualization (NFV) offers significant advantages to service providers. Not only does it facilitate cost reduction by minimizing operational expenses and hardware deployments, but it also enhances the speed of introducing new network services. Nonetheless, alongside this flexibility, companies must be mindful of critical factors, especially when transitioning Domain Name System (DNS) infrastructure to an NFV setup.

Security stands out as a domain where migrating DNS architecture to NFV poses distinct security challenges. As software increasingly oversees network functionality, a reevaluation of conventional security measures must accompany this transformation. Numerous operators are still utilizing open-source or generic software to secure the virtualized environment, which presents inherent risks that may go unrecognized. Below are several concerns emphasizing the necessity for a proactive security strategy in NFV.

• Conventional firewalls and intrusion detection systems are not tailored for safeguarding DNS, especially within the NFV context. The same versatility that allows software to offer superior flexibility and configuration compared to traditional architectures also creates more opportunities for potential misconfigurations in network functions. This vulnerability paves the way for new attack vectors, even as NFV advantages enhance security through centralization and VM-level protection. Configuration errors, even when security isn’t directly compromised, can lead to widespread network functionality issues, creating a façade of security threats where they do not exist.
• Attacks such as DNS-centric distributed denial of service (DDoS) can swiftly overwhelm network resources by flooding the DNS system with excessive resolution requests, effectively paralyzing the network and obstructing legitimate request resolution. Other types of attacks may replace valid IP addresses with those redirecting users to harmful websites or employ tunneling techniques to infiltrate individual virtual machines, compromising and exfiltrating data through channels typically overlooked by conventional security measures.
• Virtual machines afford network operations centralized control over resources and allow for the swift deployment of on-demand capabilities. However, similar to physical hardware, VMs are vulnerable to malware infections. Once a machine becomes infected and is not immediately isolated, the malware can propagate across the network, disrupting functionality from within. Monitoring the virtualized space necessitates distinct tools compared to traditional network security solutions.

As DNS-related security challenges demand increased focus during the adoption of NFV, it is imperative for carriers to validate that their security frameworks align with these requirements.

• Security for NFV should be inherently integrated within the DNS architecture, rather than implemented as an afterthought. Enhanced integration through DNS-specific protection minimizes potential coverage gaps that third-party solutions may leave exposed, thereby reducing vulnerability to attacks.
• To mitigate the consequences of attacks in real-time and resolve issues swiftly, the virtualized network must have the ability to quickly scale resources by deploying new machines independently of operator input. This automatic scaling capability during an ongoing attack prevents service disruptions and mitigates lost revenue and productivity.
• Given threats like zero-day vulnerabilities, NFV-driven security mechanisms should possess the ability to identify previously unknown threats through continual network behavior analysis, whilst defending against well-established risks such as ready-to-use attack toolkits targeting specific vulnerabilities.
• An NFV DNS security strategy must encompass both internal and external analysis along with resource tracking. While numerous threats, notably DDoS attacks, may originate externally, malware residing on existing VMs is equally perilous. The virtualized infrastructure should have the capability to monitor newly provisioned virtual machines, analyze their IP addresses, and scrutinize all traffic to identify suspicious activities in real-time. Furthermore, it should be capable of isolating VMs to curtail the spread of infections.
• Due to configuration errors leading to security and performance complications, NFV security must incorporate network discovery and automation tools to ascertain correctly configured network functions and to pinpoint potential issues.

With every technological evolution, network planning must strive to balance risks with rewards, and NFV represents a critical progression toward developing tomorrow’s highly agile, automated networks. When service providers prioritize security during the implementation phase instead of relegating it to an afterthought, the outcome is a flexible and transparent network that fulfills both current and prospective requirements while safeguarding essential resources.