An important vulnerable area in the network infrastructure, considering the attacks presented above, is made up of network devices. The targeted devices can be part of any network module and layer, including access level devices, distribution devices, or core equipment. Even though network devices (e.g., routers, switches, or other appliances) have embedded security features, you need to make sure that they are secured from intruders.
The first step is controlling physical access. Critical equipment should be placed in locked rooms that can be accessed only by authorized users, preferable via multiple authentication factors. You also want to make sure that the network administrators follow security guidelines to avoid human errors. Next, harden the network devices, just like you would harden hosts or servers, by applying the following techniques:
- Enable only the necessary services
- Use authenticated routing protocols
- Use one-time password configurations
- Provide management access to the device only through secured protocols, like SSH
- Make sure that the device’s operating system is always patched and updated to protect against the latest known vulnerabilities