Huawei H12-821_V1.0 Exam With Confidence Using Practice Dumps

Comprehensive and Detailed In-Depth Explanation:

SSH (Secure Shell) provides secure remote login and data encryption over insecure networks.

A. TRUE → SSH requires user authentication before access is granted.

B. TRUE → Enabling SSH opens listening ports, which could be scanned by attackers. Proper security measures (e.g., disabling unused SSH access) are recommended.

C. TRUE → ACLs can be applied to VTY (Virtual Terminal) lines to restrict SSH access based on IP addresses.

D. FALSE → The default SSH server port is 22, not 23. Port 23 is used for Telnet, which is less secure than SSH.

???? Reference: Huawei HCIA-Datacom Study Guide, SSH Configuration and Security Measures.

Comprehensive and Detailed Step-by-Step Explanation:

Multi-Channel Protocols:

Multi-channel protocols use separate channels for control and data communication, requiring application-specific packet filtering (ASPF) to track sessions.

Examples:

FTP (A): Uses separate control and data channels.

SIP (B): Uses multiple ports for signaling and media.

H.323 (D): A VoIP protocol using multiple channels.

Single-Channel Protocol:

SMTP (C): A single-channel protocol for email communication, which does not require ASPF.

Attributes such as community, tag, and origin can be directly referenced in the apply clause of a route-policy. However, IP-prefix is not an attribute but a prefix list used for matching, and it cannot be directly applied ​.