Centos6.5 dual card, we just need a default route, if there are two or not there will be a series of problems
[root @ centos] # vi / etc / sysconfig / network
Modify the following
NETWORKING = yes (indicate whether the system is using the network, usually set to yes. If set to no, you can not use the network, and many system services will not start)
hOSTNAME = centos (set the host name of the machine, to set the host name and where / etc corresponding to a host name / hosts set)
the gATEWAY = 192.168.1.1 (note: this needs to configure the gateway to the external network card)
Centos7 dual card, simply modify the / etc / sysconfig / network-scripts / NIC configuration file under DEFROUTE = yes
Transfer from https://www.cnblogs.com/yizhipanghu/p/10448457.html