WAN Technologies & Network Security Flashcards

Which WAN technology uses a series of virtual circuits identified by DLCIs to connect remote sites?

Answer: Frame Relay

Frame Relay uses Data Link Connection Identifiers (DLCIs) to identify virtual circuits between endpoints.

A network administrator needs to block all Telnet access to routers from outside the corporate network. Which ACL entry accomplishes this?

Answer: deny tcp any any eq 23

Telnet operates on TCP port 23, so 'deny tcp any any eq 23' blocks all Telnet connections.

What does the LMI (Local Management Interface) provide in a Frame Relay network?

Answer: Status signaling between the DTE and Frame Relay switch

LMI provides keepalive and status signaling between the router (DTE) and the Frame Relay switch at the local loop.

Which type of VPN allows remote users to securely access corporate resources over the internet using a client application?

Answer: Remote-access VPN

Remote-access VPNs use client software to allow individual users to connect securely to the corporate network.

What is the primary purpose of NAT (Network Address Translation) in a WAN environment?

Answer: To allow private IP addresses to communicate over the public internet

NAT translates private RFC 1918 addresses to public IP addresses, enabling internet access from private networks.

In PPP authentication, which protocol transmits the username and password in cleartext?

Answer: PAP

PAP (Password Authentication Protocol) sends credentials in cleartext, making it vulnerable to interception.

Which Cisco IOS command displays the status of all configured Frame Relay PVCs on an interface?

Answer: show frame-relay pvc

'show frame-relay pvc' displays statistics and status (ACTIVE, INACTIVE, DELETED) for each PVC.