202-450 Exam Dumps : LPIC-2 - Exam 202 (part 2 of 2), version 4.5

 DHCPv6 supports three types of IPv6 address assignments:

• Individual address assignment (IA_NA): This is the stateful mode of DHCPv6, where the DHCPv6 server assigns a normal IPv6 address to a client that can be renewed or released. The address is chosen from a pool of prefixes configured on the server and is unique and non-duplicate. The client can request one or more addresses using the IA_NA option in the DHCPv6 messages1
• Temporary address assignment (IA_TA): This is similar to the IA_NA mode, but the addresses assigned are temporary and cannot be renewed or released. The temporary addresses are used for privacy reasons and are generated by the client using a random interface identifier. The client can request one or more temporary addresses using the IA_TA option in the DHCPv6 messages2
• Prefix delegation (IA_PD): This is the mode where the DHCPv6 server delegates a whole IPv6 prefix to a client, such as a router or a host, that can use it for further subnetting or routing. The client can request one or more prefixes using the IA_PD option in the DHCPv6 messages. The delegated prefixes are also chosen from a pool of prefixes configured on the server3

References: 1: IP Addressing: DHCP Configuration Guide - IPv6 Access Services: DHCPv6 Individual Address Assignment 2: RFC 4941 - Privacy Extensions for Stateless Address Autoconfiguration in IPv6 3: IP Addressing: DHCP Configuration Guide - IPv6 Access Services: DHCPv6 Prefix Delegation

 The FTP names that are recognized as anonymous users in vsftpd when the option anonymous_enable is set to yes in the configuration file are anonymous and ftp. These are the default names that vsftpd accepts as valid anonymous users, and they can be used interchangeably. The anonymous user does not need to enter a password, but can optionally enter an email address as a password. The anonymous user has limited permissions and can only access the directory specified by the anon_root directive, which is usually /var/ftp or /srv/ftp. The anonymous user can download files from the server, but cannot upload or modify files, unless the anon_upload_enable and anon_mkdir_write_enable directives are also set to yes.

The other options are not recognized as anonymous users in vsftpd. Option C is incorrect, because vsftpd will reject any username that does not belong to an existing user or an anonymous user. Option D is incorrect, because nobody is a system user that has no permissions and is not related to FTP. Option E is incorrect, because guest is not a valid FTP name, unless the guest_enable directive is set to yes, which will make all non-anonymous users log in as the guest_username, which is usually ftp.

References:

• vsftpd.conf - config file for vsftpd
• How To Set Up vsftpd for Anonymous Downloads on Ubuntu 16.04
• How to Configure vsftpd FTP Server on CentOS 8

The commands nc and telnet can be used to connect and interact with remote TCP network services. nc stands for netcat, a utility that can read and write data across network connections using TCP or UDP protocols. telnet is a client-server protocol that allows a user to communicate with a remote host using a virtual terminal. Both commands can be used to test the connectivity and functionality of network services such as web servers, mail servers, FTP servers, etc. by specifying the host name or IP address and the port number of the service. References:

• LPIC-2 exam 201 topics, section 205.1, “Use and configure network monitoring tools”.
• LPIC-2 exam 202 topics, section 208.1, “Implementing a web server”.
• Linux Essentials 010 exam objectives, section 4.3, “Basic network configuration and troubleshooting”.