When to Use Out-of-Band Management

AB

Out-of-band management refers to managing network devices using a separate network dedicated solely to management traffic. In contrast, in-band management uses the same network that carries production traffic to manage network devices.

Out-of-band management is generally considered more secure and reliable than in-band management, as it is not susceptible to the same network congestion and security threats that can impact production traffic. Out-of-band management is particularly useful in the following situations:

A. When a network device fails to forward packets: If a device is not forwarding packets, it may be inaccessible using in-band management. In such a scenario, out-of-band management can be used to access the device and troubleshoot the issue. This is possible because out-of-band management traffic is sent to a separate management interface on the device, which may not be impacted by the packet forwarding issue.

B. When you require ROMMON access: ROMMON (Read-Only Memory Monitor) is a bootstrap program that allows you to recover a device that is unable to boot normally. ROMMON access is generally required in cases where the device has experienced a catastrophic failure, such as a corrupted operating system image. Out-of-band management is useful in such situations because it allows you to access the device's ROMMON prompt and recover the device without relying on in-band management.

C. When management applications need concurrent access to the device: In some cases, multiple management applications may need to access a device simultaneously. This can lead to network congestion and slow down production traffic if in-band management is used. Out-of-band management allows each management application to have a dedicated management interface on the device, ensuring that there is no impact on production traffic.

D. When you require administrator access from multiple locations: If administrators need to access a device from multiple locations, out-of-band management can provide a secure and reliable way to do so. Each administrator can access the device using a separate management interface on the out-of-band network, ensuring that there is no impact on production traffic.

E. When the control plane fails to respond: In some cases, the control plane of a network device may fail to respond, making it inaccessible using in-band management. Out-of-band management can be used to access the device and troubleshoot the control plane issue. This is possible because out-of-band management traffic is sent to a separate management interface on the device, which may not be impacted by the control plane issue.