Basic Linux Network Configuration

Basic Linux Network Configuration

1. TCP/IP network configuration file

/Etc/sysconfig/network-scripts/ifcfg-eth0

/Etc/sysconfig/network

/Etc/host. conf

/Etc/hosts

/Etc/resolv. conf

/Etc/services

(1)/etc/sysconfig/network-scripts/ifcfg-eth0

Network Interface Startup Script

Content instance:

DEVICE = eth0

ONBOOT = yes

BOOTPROTO = static

IPADDR = 192.168.1.10

NETMASK = 255.255.255.0

GATEWAY = 192.168.1.1

NETWORK = 192.168.1.0

BROADCAST = 192.168.1.255

(2)/etc/sysconfig/network

Basic Network Information Configuration

Content instance:

NETWORKING = yes

HOSTNAME = linux.jnrp.cn

GATEWAY = 192.168.1.1

(3)/etc/hosts

The/etc/hosts file is the local host name resolution database of the system.

Content instance:

# Do not remove the following line, or various programs

# That require network functionality will fail.

127.0.0.1 localhost. localdomain localhost

192.168.1.2 CentOS5

(4)/etc/host. conf

The/etc/host. conf file is used to specify how to resolve the host name. Available options include:

Order: Set the available methods and sequence for host name resolution. Available methods include hosts (using the/etc/hosts file for resolution) and bind (using DNS Server Resolution), nis (using Network Information Service NIS resolution)

Multi: sets whether to return multiple IP addresses of the host from the/etc/hosts file. The value is on/off.

(5)/etc/resolv. conf

The/etc/resolv. conf file is the client configuration file of the DNS domain name service.

Content instance:

Nameserver 218.30.19.40

Nameserver61.134.1.4

Search jnrp.cn

Domain jnrp.cn

(6)/etc/services

Set the default TCP or UDP port used by the Network Service

File Content instance:

# Each linedescribes one service, and is of the form:

#

# Service-name port/protocol [aliases...] [# comment]

Tcpmux 1/tcp # TCP port servicemultiplexer

Tcpmux 1/udp # TCP port servicemultiplexer

Ipve 5/tcp # Remote Job Entry

Rje 5/udp # Remote Job Entry

Echo 7/tcp

Echo 7/udp

Discard 9/tcp sink null

Discard 9/udp sink null

Listen at 11/tcp users

Protocol at 11/udp users

2. Use the command line tool to configure the network

Basic network configuration command:

Ifconfig

Ifup

Ifdown

Hostname

(1) ifconfig command

The ifconfig command is used to view and Configure TCP/IP networks.

Command instance:

# Ifconfig eth0

Eth0 Link encap: Ethernet HWaddr 00: 0C: 29: FB: E4: 89

Inet addr: 192.168. 1.3 Bcast: 192.168. 1.255 Mask: 255.255.255.0

Inet6 addr: fe80: 20c: 29ff: fefb: e489/64 Scope: Link

Up broadcast running multicast mtu: 1500 Metric: 1

RX packets: 36 errors: 0 dropped: 0 overruns: 0 frame: 0

TX packets: 139 errors: 0 dropped: 0 overruns: 0 carrier: 0

Collisions: 0 FIG: 1000

RX bytes: 4321 (4.2 KiB) TXbytes: 13153 (12.8 KiB)

Interrupt: 10 Base address: 0x1400

# Ifconfig eth0 192.168.1.3 netmask 255.255.255.0

(2) route command

The route command is used to set the route information of the Linux system.

View route information:

Route-n

Add a static route entry

Route add-net netaddr netmask gw ipaddr dev

Set the Default Gateway

Route add default gw ipaddr

Delete A route entry

Route del-net netaddr netmask gw ipaddr dev

Ping Command to test network connection through ICMP protocol

The traceroute command can trace the path to a specific destination.

The netstat command is used to view various network-related status information, including the network connection status, interface statistics, and route table and port monitoring information.

(3) ping command

The basic usage of the ping command is:

Destination Address of the ping Option

Common options include:

-C: specify the number of ICMP messages sent by the ping command. If this parameter is not specified, the ICMP messages will be sent continuously until you press ctrl + c to stop the command.

-I: Specifies the interval between the ping command and each ICMP message. The default value is 1 second. For security reasons, only super users can set this value to less than 0.2 seconds.

-S: sets the size of each ICMP message. The default value is 64 bytes and the maximum value is 65507.

-T: Set ttl (Time to Live)

(4) traceroute command

(5) netstat command

Common netstat Commands include:

-A: displays all listening and non-listening sockets.

-I: displays statistics of interfaces.

-N: the IP address and port are displayed in numbers instead of names.

-P: displays the PID and program name of the process using the port.

-R: displays the kernel route table.

-S: displays statistics for each protocol