Network management is a critical aspect of IT infrastructure, involving the control, monitoring, and maintenance of network devices. There are two primary methods for managing network devices: in-band and out-of-band (OOB) management. Understanding these concepts and their applications can significantly enhance network reliability and security.
In-Band Management
In-band management refers to accessing and managing network devices over the same data network used for regular communications. This method leverages existing network connections and protocols to perform management tasks.
Security & Mitigation
In-band management plays a crucial role in mitigating security threats by ensuring that management traffic is securely tunneled through a Virtual Private Network (VPN). Here’s how it works:
VPN Overlay: By creating a VPN overlay, network administrators ensure that all management traffic is encrypted and secure. The overlay serves as the exclusive path for management access, isolating it from regular network traffic.
Call Home Agents: Devices at the network edge can be equipped with call home agents, which initiate a connection to the central management system. This method ensures that only authenticated devices can communicate with the management server.
Telemetry and Stability: Using the VPN overlay for telemetry ensures that monitoring data is securely transmitted. This approach is more stable when using protocols like UDP, as it reduces latency and packet loss.
WireGuard Implementation: When available, WireGuard can be used to establish secure VPN connections due to its simplicity, speed, and strong cryptographic guarantees.
Implementation Variations
The implementation of in-band management can vary based on the router and networking hardware. While many projects offer central management portals for WireGuard-based setups, these can sometimes be overly complex, increasing the attack surface. Thus, a streamlined, secure implementation is preferable.
Out-of-Band Management
Out-of-band (OOB) management provides an alternative by using a separate, dedicated management channel independent of the primary data network. This method typically involves physical connections, such as console cables, to access network devices directly.
OOB is there to save your bacon when you end up in a situation where you saw the log on the wrong side!
Simplicity & Reliability
OOB management forces network management into its simplest and most reliable form:
Console Cables: Using console cables for OOB management ensures direct access to the device’s command-line interface (CLI), bypassing the primary network. This method is extremely reliable as it does not depend on network availability.
Critical Infrastructure: For any critical infrastructure, such as data centers, points of presence, or essential customer links, having console access is paramount. This ensures that even if the network is down, administrators can still manage and troubleshoot devices.
Remote Hands: Combining OOB management with remote hands minimizes human intervention risks. Remote hands can assist in physical access, but the reliance on direct console access reduces the potential for errors or misconfigurations.
Practical Insights
A network engineer without a rollover cable is akin to someone forgetting essential personal hygiene items. It’s a fundamental tool for ensuring network reliability. Fusion SD-WAN offers a unique advantage by enabling OOB management via console cables connected to the SD-WAN device’s USB port, allowing CLI access to third-party infrastructure. This capability can be a lifesaver in critical situations.
Integration of In-Band & Out-of-Band Management
Both in-band and OOB management should be viewed as complementary processes rather than standalone products. Effective network management involves planning for console access OOB for any valuable infrastructure, whether it’s at home, in a business, or at a data center. This approach mitigates risks associated with network failures and ensures continuous management capabilities.
Case Study | Practical Application
Consider a scenario where a business has a critical R12000 DFA link or even a single consumer-grade link. When these links fail, the consequences are similar, highlighting the importance of robust management strategies. In early releases of Mikrotik’s V7 firmware, configurations would sometimes fail, necessitating the use of console cables for OOB management. Despite improvements in later releases, the presence of these cables still provides a safety net for network administrators.
Hardware
In a bind it is possible to add access of last resort using a KVM switch or device such as these:
Wrap
In-band and out-of-band management are essential strategies for maintaining network reliability and security. In-band management, with its VPN overlay and secure telemetry, mitigates security threats, while OOB management, with its direct console access, ensures continuous device management. Combining these approaches, especially in critical infrastructure, provides a comprehensive solution for robust network management. By leveraging tools like Fusion SD-WAN and planning for both in-band and OOB management, businesses can enhance their network resilience and operational efficiency.
Ronald Bartels ensures that Internet inhabiting things are connected reliably online at Fusion Broadband South Africa - the leading specialized SD-WAN provider in South Africa. Learn more about the best SD-WAN provider in the world! 👉 Contact Fusion
