SMTP mail Service IPv6 advanced network configuration

################## #邮件服务 ########################

1. Related concepts and preparatory work

SMTP: (Simple Mail Transfer Protocol) is simply Mail Transfer Protocol, which is a set of rules for sending messages from source to destination to control how the letters are transferred. The SMTP protocol belongs to the TCP/IP protocol cluster, which helps each computer find the next destination when sending or relaying letters. The server specified by the SMTP protocol, you can send e-mail to the recipient's server, the whole process only a few minutes. The SMTP server is the outgoing mail server that follows the SMTP protocol and is used to send or relay outgoing e-mail messages.

Dovecot: is an open-source IMAP and POP3 Mail server that supports the Linux/unix system.

POP: The full name of the post Office Protocol, the Post Office Protocol, is used for receiving e-mail, which uses TCP's 110 port. Now commonly used is the third edition, so referred to as POP3.

IMAP (Internet Mail access protocol,internet) is formerly known as an interactive Mail Access Protocol (Interactive Mail access Protocol). IMAP was a mail acquisition protocol developed by Stanford University in 1986. Its primary role is that mail clients (such as Ms Outlook Express) can obtain messages from mail servers, download messages, and so on through this protocol. The current authoritative definition is RFC3501. The IMAP protocol runs on top of the TCP/IP protocol and uses a port of 143. The main difference between it and the POP3 protocol is that the user can not download all the mail, and can directly operate the Mail on the server through the client.

Required services bind (named DNS server) phpmysqladmin PHP php-mysql postfix mariadb-server Thunderbird (mail client) mutt (email program)

Preparation: Configure network of two virtual machines and DNS servers

2. Configure Postfix to enable two virtual functions to send messages to each other

Vim/etc/postfix/main.cf

Test DNS and Postfix configuration results

Empty Shell Mail

Vim/etc/posfix/virtual.

3 Configuration dovecot.conf

4. Install phpmysqladmin and create a database

5. Use mutt to view Mail on the client, Mutt is an email program under Linux, similar to a File Manager mail management tool.
Yum Install mutt-y ### #安装
Mutt-f pop://student@172.25.254.2
Login in Enter student password, will error exit.
Go to mailserver host Cat/var/log/maillog view the error
According to the error message, you should create an. IMAP directory in/home/student/mail/with student identity, and create a Inbox file under that directory

#################### #IPv6配置 ######################

######################### #高级网络配置 ############################

1. Bridge connection

Bridging (bridging) refers to the process of forwarding a network packet based on the address of the link layer of the OSI network model, working on the second layer of OSI. The general switch, the Network Bridge has the bridge function.

Bridge is an early two-tier network device used to connect different network segments. The two ports of the bridge have a separate switching channel, which is not to share a backplane bus, and can isolate the conflict domain. The network bridge is better than the hub (hub), and the ports on the hub share the same backplane bus. Later, the network Bridge is replaced by a switch that has a more multiport port and is also able to isolate conflicting domains.

Bridge is like a smart repeater. The repeater receives signals from a network cable, magnifies them, and feeds them into the next cable. By comparison, the bridge is more sensitive to the information uploaded from the checkpoints. Network Bridge is a kind of frame forwarding technology, according to Mac block, can be isolated collision. A network bridge connects multiple segments of the network to the data link layer.

The bridge is also called a bridge, a storage/forwarding device that connects two LANs, which splits a large LAN into multiple network segments, or interconnects more than two LANs into a single logical LAN so that all users on the LAN can access the server.

Bridging is a function of a network device, and the bridge is a network device.

Brtctl Control general Operations this control needs to be turned off network Manager shuts down this service cannot configure the network in the graphical interface, only through configuration file configuration

Brctl # # #桥接管理命令

–show # # #显示

–ADDBR # # #添加网桥

–DELBR # # #删除网桥

–ADDIF # # #添加网桥连接

–delif # # #删除网桥连接

2.bond Network

Bond network Red Hat Enterprise Linux allows administrators to bind multiple network interfaces to one channel using bonding kernel modules and special network interfaces called channel binding interfaces. Depending on the binding pattern you select, channel bindings make two or more network interfaces as a network interface, increasing bandwidth and/or providing redundancy

Mode 0 (Balanced round robin)-a round robin strategy in which all interfaces transmit packets in all Slave using a round robin method; any Slave can receive

Mode 1 (active backup)-fault tolerance. Only one Slave interface can be used at a time, but if the interface fails, another Slave will replace it

Mode 3 (broadcast)-fault tolerance. All packets are broadcast through all Slave interfaces

Using the NMCLI command to manage Bond

nmcli con Add type Bond con-name BOND0 ifname bond0 mode active-backup nmcli con mod bond0 ipv4.addresses 1.2.3.4/24

nmcli con Add type bond-slave ifname eth0 master bond0 con-name bond0-eth1

nmcli con Add type bond-slave ifname eth1 master bond0 con-name bond0-eth2

• Configure system Load Binding module:/etc/modprobe.d/bonding.conf–alias bond0 Bonding

ifenslave bond0 eth0 eth1

• View bonding Status –cat/proc/net/bonding/bond0

3.team interface

team and BOND0 functions are similar team do not need to manually load the corresponding kernel modules team has a stronger scalability-Support 8 network card

Type of Team

broadcast broadcast fault tolerance

Roundrobin Polling

Activebackup Main Preparation

LoadBalance Load Balancing

Configuration method:

nmcli con Add type team con-name TEAM0 ifname team0 config ' {' runner ': {' name ': ' LoadBalance '}} '

nmcli con mod team0 ipv4.addresses 1.2.3.4/24

nmcli con mod team0 ipv4.method Manual

nmcli con Add type team-slave ifname eth0 master team0 con-name team0-eth1

nmcli con Add type team-slave ifname eth1 master team0 con-name team0-eth2