Common commands and configuration files for Linux networks

Introduced

• Network, is a very big topic. If you want to learn about the OSI seven layer model and want to see what the Network Bridge, routers and other networking devices look like, you may be disappointed here. However, for those who are not getting started or just getting started, English is not good for the Internet, you find the right article. Below, let me introduce the common web-related commands and configuration files in CentOS, so that you can easily configure the Internet.

ifcfg Family: Net-tools

This is an ancient family that accesses and changes the kernel network configuration through PROCFS (/PROC) and IOCTL system calls. After CENTOS6, it is recommended to replace it with the Iproute2 family, but as a classic network series, it is worthwhile to take a moment to understand it.

ifco

Ifconfig  [interface]    ifconfig interface [aftype] options  | address ...        # ifconfig: Display the active status of the NIC interface;          # ifconfig -a: Displays all interfaces, including the inactive interface;         # ifconfig  iface  ip/mask  [up|down]              Example:   enable eth0 this NIC:                      Ifconfig  eth0  up         # ifconfig   IFACE  IP  netmask  NETMASK                example:  to eth0 this NIC set IP to 1.1.1.1, subnet mask is 255.0.0.0:                     ifconfig eth0 1.1.1.1  netmask 255.0.0.

Route: Routing Table Management

     Routing Entry Type:         host route: The destination address is a single ip;          Network routing: Destination address is IP network;         Default route: target for any network,0.0.0.0/0.0.0.0     view:# route  -n     Add:route  add  [-net|-host]  target  [netmask  nm]   [gw GW]  [[dev] If]         Example:             1. Add a new route to 10.0.0.0/8, the gateway is 192.168.234.1, the corresponding network card is eth1;                 route add  -net  10.0.0.0/8  gw  192.168.234.1  dev  eth1                  or                  route add  -net  10.0.0.0/255.0.0.0   Gw 192.168.234.1              2.   Add a new default route, gateway to 192.168.234.1                 route add  default  gw 192.168.234.1           Delete:        route  del   [-NET|-HOST] TARGET  [GW GW]  [NETMASK NM]  [[DEV] IF]          Example: route  del  -net   10.0.0.0/8  gw 192.168.10.1                route  del  default

Note: when adding a route entry, the gateway must be in the same network segment as the associated network card IP, or the network is unreachable error will occur.

ARP: administering the ARP cache table

View ARP table: Arp-en add static ARP entry: arp-s 192.168.234.100 00:0c:29:c0:5a:ef Delete static ARP entry: arp-d 192.168.234.100

Netstat: status and Statistics view

Show routing table: Netstat-rn-r: Show kernel route table-N: Number format display network connection: netstat [options] options:-T:TCP protocol related connection, connection its status; FSM (finate state machine);-U:UDP related connection-w:raw socket related connection-L: Connection in listening state-A: all states-N: Digital format displays IP and port;-e: Extended Format-P: Displays related processes and PID; common combinations:-tan,-uan,-TNL,-UNL,-TUNLP

Ifup/ifdown command:

The configuration file/etc/sysconfig/network-scripts/ifcfg-iface to identify the interface and complete the configuration; Example: Ifdown eth0 + ifup eth0 <==> Read profile restart Eth0

• Iproute2 Family:

This is the connection to the kernel via the network link socket interface. The network link interface is lighter than the/proc interface, and more importantly, binding operations such as source-based routing, quality of service, and so on, must be iproute2 to complete. so you're still using net-tools, and it's time to switch to Iproute2 .

Ip:

Addr: Address and mask;

Link: interface

Route: Routing

viewing ARP Tables

You can use these commands to display the ARP table for the kernel.

Using Net-tools:

$ arp-an

Using Iproute2:

$ IP neigh

SS: Status and Statistics view

This article is from the "home of small Mosquitoes" blog, be sure to keep this source http://timber.blog.51cto.com/7677013/1728750

Common commands and configuration files for Linux networks