Linux note 10--Routers, DNS,DHCP configuration

# # Router # #

1 . Router--The main function is to do NAT
Dant Destination Address Translation
Snat Source Address Translation

2 . Gateway--The IP on the router and itself on the same network segment

3 . Set the Gateway
Global Gateway
Systemctl Stop NetworkManager
Vim/etc/sysconfig/network
gateway= Gateway IP
Nic Interface Gateway
vim/etc/sysconfig/netw/work-scripts/ifcfg-NIC configuration file
gateway= Gateway IP
Systemctl Restart Network

Example: Setting up a gateway

Setting a global Gateway

A. Close the NetworkManager service

B. Modifying a configuration file

C.. Restart the network to view the gateway

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Setting the NIC interface Gateway

A. Modifying a configuration file

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B. Restart the network

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4 . View the Gateway

Route-n

## DNS Server # #
1 . dns--This server provides a function to answer the client hostname and IP correspondence

2 . Setting up DNS
Vim/etc/resolv.conf
NameServer DNS Server IP

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vim/etc/sysconfig/network-scripts/ifcfg-NIC configuration file
Dns1=dns Server IP

3 . Local parsing file
Vim/etc/hosts
IP host Name

4 priority tuning of local parsing files and DNS reads
Vim/etc/nsswitch.conf
the : The Hosts files DNS files represent the local parsing file. DNS represents the DNS server, the one in front of that high priority

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## DHCP configuration file # #
Yum Install Dhcp-y
cp/usr/share/doc/dhcp-4.2.5/DHCPD.CONF.EXAMPLE/ETC/DHCP/DHCPD

<<< unit exercises >>
1 when executing set-ip-tool *) automatically displays the output of the ifconfig command
*) The system IP is set to: *) The system gateway is set to: 172.25.254.250
*) system DNS was set to: 172.25.254.250

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Linux note 10--Routers, DNS,DHCP configuration