This machine has a public IP address (x.x.x.x) and a private IP address (192.168.1.102). Trying to get NetworkManager to assign both of those to a single ethernet port was an exercise in frustration - I could either get one or the other, but not both IP addresses available at the same time. A lot of the time 'ifconfig -a' would show one, neither or both of the "configured" IP addresses, and there was no logic to whether the interface would work or not.
So, nix NetworkManager.
Code: Select all
[root@xanadu]# systemctl status NetworkManager
● NetworkManager.service - Network Manager
Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; disabled; vendor preset: enabled)
Active: inactive (dead)
Docs: man:NetworkManager(8)
Code: Select all
[root@xanadu]# ls -1 /etc/sysconfig/network-scripts/ifcfg*
/etc/sysconfig/network-scripts/ifcfg-eth0
/etc/sysconfig/network-scripts/ifcfg-eth0:1
/etc/sysconfig/network-scripts/ifcfg-lo
[root@xanadu]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=eth0
HWADDR=10:7B:44:90:34:7B
DEVICE=eth0
ONBOOT=yes
DNS1=192.168.1.254
DOMAIN=gornall.net
IPV6_PRIVACY=no
IPADDR=<public-address>
NETMASK=<public-netmask>
GATEWAY=<public-gateway>
DNS2=8.8.8.8
PREFIX=24
[root@xanadu]# cat /etc/sysconfig/network-scripts/ifcfg-eth0:1
TYPE=Alias
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=eth0
HWADDR=10:7B:44:90:34:7B
DEVICE=eth0
ONBOOT=yes
DNS1=192.168.1.254
DOMAIN=gornall.net
IPV6_PRIVACY=no
IPADDR=192.168.1.102
NETMASK=255.255.255.0
GATEWAY=192.168.1.254
DNS2=8.8.8.8
PREFIX=24
At this point, doing a 'systemctl restart network' will recover the network, and everything is sweetness and light again. At the moment my stopgap is to have cron run this every 5 minutes...
So, what is causing me to drop my network interface ? Is it some last vestige of NetworkManager that I don't know about, or it crossed my mind it could be a cron-job (but I can't find anything in the crontabs), or maybe power-management is switching the interface off ? Is there an easy way to turn off power management on Centos 7 ? I couldn't see anything in the BIOS that was related to power-management...
Any hints gratefully received