Which two host names follow the guidelines for naming conventions on Cisco IOS devices?

The name "RM-3-Switch-2A4" adheres to Cisco's naming conventions for several reasons. Firstly, it uses hyphens as separators, which are acceptable in hostnames. This style allows for clarity and organization in naming multiple components, such as identifying the type of device (in this case, a switch) and its location or function. Additionally, it avoids special characters that are not recommended, ensuring compatibility across various network management systems and interfaces.

In contrast, the other options break Cisco's naming rules in different ways. For instance, "SwBranch799" uses a format that varies from traditional conventions, as while it combines letters and numbers, it might sacrifice clarity if not adequately structured. "Router_1" employs an underscore, which is not permitted in Cisco IOS hostnames. Lastly, "Switch@Main" contains an '@' symbol, which is also not allowed in hostnames under Cisco naming guidelines. Therefore, "RM-3-Switch-2A4" is the best representation of an acceptable naming convention for Cisco IOS devices.