Linux Network Infrastructure 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

Startup scripts for network interfaces

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

Network basic Information configuration

Content instance:

Networking=yes

hostname=linux.jnrp.cn

gateway=192.168.1.1

(3)/etc/hosts

/etc/hosts file is the local hostname resolution database for the system

Content instance:

#Do not remove the following line, or various programs

#that require network functionality would 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 host names are resolved, and the available options are:

Order: Sets the available methods and order of host name resolution, including the hosts (parsing with the/etc/hosts file), 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, with a value of on/off

(5)/etc/resolv.conf

/etc/resolv.conf file is a client configuration file for 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 TCP or UDP port used by the network service by default

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

Rje 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

Systat 11/TCP Users

Systat 11/UDP Users

2. Configure the network with command-line tools

Basic Network Configuration commands:

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 txqueuelen: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 routing information for a Linux system

To view routing 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 Commands network connectivity testing over the ICMP protocol

The traceroute command tracks the path through which a destination is reached

The netstat command is used to view various network-related status information, including: Network connection status, interface statistics, view routing table, port monitoring, etc.

(3) Ping command

The basic usage of the ping command is:

Ping option Destination Address

Common options include:

-C: Specifies the number of ICMP messages emitted by the ping command, if not specified, will be sent continuously until the user presses the "CTRL + C" Abort command

-I: Specifies the time interval between each ICMP message that the ping command emits, with a default value of 1 seconds. For security reasons, only super users can set this value to less than 0.2 seconds

-S: Sets the packet size for each ICMP message emitted, which defaults to 64 bytes and a maximum value of 65507

-T: Set TTL (Time to Live)

(4) Traceroute command

(5) Netstat command

Common options for the netstat command include:

-A: Displays all listening and non-listening sockets

-I: Display statistics for interfaces

-N: Displays IP addresses and ports in digital form instead of names

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

-R: Show kernel routing table

-S: Display statistics for each protocol

Linux Network Infrastructure configuration