Linux network settings (version 2)-Linux network settings

Linux network settings (version 2)-Linux network settings
Linux network settings-network configuration file and command network configuration file

1./etc/sysconfig/network-scripts/ifcfg-eth0 # [Save the IP address and gateway]

[Set static IP addresses]

IPADDR = new IP address # This option sets the IP address. If BOOTPROTO = dhcp is set and the IP address is automatically obtained, this option is not available. Otherwise, it is BOOTPROTO = no.

GATEWAY = GATEWAY # specify a GATEWAY

BROADCAST = BROADCAST address

NETMASK = Subnet Mask

2./etc/sysconfig/network # Save the local host name

HOSTNAME = host name # specify the host name. If dhcp is specified for automatic allocation, this option is not available because the host names are all localhost.

3./etc/rc. d/init. d/network start/stop/restart network Startup Script

Or service network restart

If a static IP address is set, restart the system, or reload the following STARTUP script. The setting takes effect. However, the latter is recommended!

4./etc/hosts # saves the domain name database

5./etc/services # stores network service information, such as ports and transmission protocols.

6./etc/resolv. conf # specify the DNS server address

Nameserver [DNS Server IP address] # Add a DNS server. You can specify multiple DNS server addresses with spaces. Up to three DNS server addresses can be used.

Appendix-the service program may not use a fixed port, but the WebServer exposed to the outside will not change the port, but it is recommended to change the port like SSH to avoid Scanning

Nmap [IP address] # scan the host to enable those services, but it only scans the ingress port or the port of the well-known service by default.

Network management commands

1. ifconfig # view network port settings

Ifconfig eth0 up/down # enable/disable the NIC

2. ethtool [Nic name] # detect Nic line connection

Ethtool eth0

Ethtool wlan0

The ethtool command is very important when multiple NICs exist on a server!

3. arp # view ARP table information, as shown in the preceding figure.

4. ping # detect remote hosts

Ping-c 10-s 1000 IP address #-c specifies the number of ping requests, and-s specifies the size of sent packets. Pay attention to the packet loss rate during ping.

5. route # operate the route table

Route add default gw 192.168.14.100 # add a gateway without modifying the configuration file

[But it is better to modify the configuration file]

Zerba routing software]

6. traceroute # view the route path

Traceroute www.163.com # it lists all the routers and latencies that pass through the host.

7. netstat # monitor the network status

Netstat-an # view all connections

Netstat-an | grep: 80 # Check whether the Apache service is started