Discover the 10 essential things you need to know about Out-of-Band Networks. Big Network provides insights into why these networks exist, how they enhance network resilience, and how modern OOB networks are cost-effective and efficient.
Out of Band Networks are highly effective means to improve network resilience: they provide network engineers and site reliability engineering teams alternative methods to access key infrastructure operating in the datacenter, the edge, or the cloud. Today's demands for uptime and availability of even the most basic applications can leverage out of band networks to enhance the ability to recover from outages quickly and recover network resilience.
Big Network has compiled a list of 10 things everyone should know about out of band networks:
An out of band network is a means to access your infrastructure, such as servers, network equipment, firewalls, routers, and other IT devices when your primary path for access is down.
On the Internet, everyone has a bad day once in a while. From the largest social media sites to clouds and to e-commerce, complex IT systems have problems; operators make errors with configuration, network automation software has bugs, and distributed denial of service (DDoS) attacks happen. An out of band network gives operators a dedicated path that is separate for key tasks or gets around outages in the primary path.
In-band signaling happens via your primary, general purpose connections in and out of your environment. For example, in a datacenter context, in-band signaling would happen over your primary internet connections like BGP fed Dedicated Internet Access (DIA). Out of band signaling happens over its own, dedicated channel away from the production network and is primarily used for network management functions.
Deploying an out of band network requires careful planning, equipment and software selection, and implementation. First and foremost, it is key to create a separate path into your environment away from the main production path:
The key is that this is a /different/ data path that is not available to the general consumer of your services.
The key is that this is a /different/ data path that is not available to the general consumer of your services.
From there, selecting the appropriate equipment and software is required. OOB hardware should be low in power consumption, offer a variety of WAN and LAN ports, and the software should enable secure remote access to the environment at hand.
It certainly was the case that OOB networking related to serial ports in older times of networking. Legacy networking gear often provided users with a “console” port, which provided serial access to the device from a local workstation. Serial terminal servers were used to gateway from ethernet networks to serial connections for remote access.
In 2022, most modern networking devices offer both serial console connections and dedicated management ethernet connections. Importantly, both of these pathways are dedicated paths for secure remote management out of the main data plane of devices.
Network resilience engineering (NRE) is a relatively new practice in the world of IT. NRE focuses on network design and architecture so that networks remain available and stable during routine and unexpected failures. NREs use tools like network simulators, pre-production environments, and labs to evaluate network designs and stability.
However, this is no substitute for real-world testing. “Pull the plug” tests are the strongest way to test your network resilience, and it is during these tests that OOB networks provide the backup path for visibility and observability.
A modern OOB network should implement at least the following features:
They don’t have to be! Software Defined Networking (SDN) technology allows OOB networks to be flexibly and robustly designed across a variety of platforms. SD-WAN removes the need for costly leased lines and dedicated MPLS or VPLS solutions.
The components to a modern OOB network include:
Often, the big cost in legacy OOB solutions is the site-to-site dedicated networking,particularly in the form of leased lines and/or MPLS services. An SD-WAN and VPN-based solution, carried over commodity DIA, can offer a more robust resiliency profile at a fraction of the cost.
OK, well, you asked, and three big ones come to mind:
Rogers, a Canadian ISP, took a nationwide outage across wired and wireless networks across their entire footprint. Given the extensive nature of the outage and duration of the event, it is safe to assume that both in-band and out of band methods were hampered.
Facebook takes a global outage. In their post-event blog publication, we learned that their recovery efforts were inhibited due to dependencies in their OOB network design that didn’t make their between quite as out of band as they thought…real diverse OOB is needed!
Centurylink experienced a nationwide outage due to FlowSpec rule deployment, which hampered their remote access to the affected routers. Robust and diverse out of band could have provided a valuable safety net in applying, then backing out, the FlowSpec rule.
Big Network provides a cloud orchestrated, secure, and robust networking solution to build OOB networks:
