Configuring Static IP Addresses in Centos 7

harshld · 11-29-2016, 03:47 AM

I am trying to assign static IP address to Centos 7 with the commands

vim /etc/sysconfig/network-scripts/ifcfg-ens33

I can edit and it is saving but when i try checking for configs through ifconfig it is the same ip as of earlier through dhcp. using centos in a virtual environment of VMware.

please suggest.!!!!

wpeckham · 11-29-2016, 05:20 AM

I suggest that after changing any network scripts you do a restart on your networking (or reboot) since the changes only take effect on network start.

By the way, if you intended to show us the cfg file contents inside a CODE block, that did not work.

szboardstretcher · 11-29-2016, 08:28 AM

Centos 7, after making changes:

Code:

systemctl restart network.service

harshld · 12-01-2016, 04:06 AM

Quote:

Originally Posted by szboardstretcher

Centos 7, after making changes:

Code:

systemctl restart network.service

Thanks, that did help. I was able to configure a static IP in centos but now it does not have any connectivity to internet.

I am using CENTOS 7 in VMWare, earlier the IP address (dhcp) was 192.168.139.135, but now when I assigned 192.168.139.100, it can neither ping any website or connect in any manner.

ping google.com
ping: unknown host google.com

this is the output when I try to do ping.

is there anything I am missing in vim /etc/sysconfig/network-scripts/ifcfg-ens33

TYPE=Ethernet
BOOTPROTO=none
IPADDR=192.168.139.100
NETMASK=255.255.255.0
GATEWAY=192.168.139.2
DOMAIN=majan.com
DNS1=192.168.139.100
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=yes
NAME=ens33
UUID=5f06d8d9-273b-45a8-807b-35e2e27c840f
DEVICE=ens33
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes

this is what I entered.

Please help.

Jjanel · 12-01-2016, 04:53 AM

Can you ping by ip#? Like: ping 8.8.8.8? IF not, post: ip a;ip r
DNS1=192.168.139.100 [==] IPADDR=192.168.139.100
doesn't look 'good IMHO': I doubt that this is its own DNS server! Try MAYBE:
DNS1=192.168.139.2 (the gw, or 8.8.8.8)

wpeckham · 12-01-2016, 05:48 AM

Following the advice given by Jjanel will determine if the problem is in the routing, or only in DNS resolution.
Generally, any good ISP will provide at least TWO DNS servers, but I always include a third that is a fast public DNS. The nameserver at 8.8.8.8 is a public DNS provided by google. They also provide a backup at 8.8.4.4, and LEvel3 communications offers 4.2.2.2, but there are MANY others. In your file settings are allowed for DNS1=, DNS2=, and DNS3=. Technically you can assign as many as you like, but the network stack will only ever use the first three: and only the first ONE if it always responds.