RHEL 7 and Network Manager DHCP Issues

So at $work we’ve decided to start using DHCP for assigning addresses to our severs. I’ll write up a post on why, but I assure you, it’s a good enough reason.
Any way, I noticed the other day that my webserver was consistently losing the connection to our MySQL database. Looking into the logs, it occurred every time DHCP went to renew the lease.


Sep 18 08:20:59 xxxxx dhclient[652]: DHCPREQUEST on eno16780032 to 10.21.x.x port 67 (xid=0x68397b65)
Sep 18 08:20:59 xxxxx dhclient[652]: DHCPACK from 10.21.3.2 (xid=0x68397b65)
Sep 18 08:20:59 xxxxx NetworkManager[595]: address 10.21.x.x
Sep 18 08:20:59 xxxxx NetworkManager[595]: plen 24 (255.255.255.0)
Sep 18 08:20:59 xxxxx NetworkManager[595]: gateway 10.21.x.1
Sep 18 08:20:59 xxxxx NetworkManager[595]: server identifier 10.21.x.x
Sep 18 08:20:59 xxxxx NetworkManager[595]: lease time 3600
Sep 18 08:20:59 xxxxx NetworkManager[595]: nameserver '10.21.x.x'
Sep 18 08:20:59 xxxxx NetworkManager[595]: nameserver '10.21.x.x'
Sep 18 08:20:59 xxxxx NetworkManager[595]: domain name 'xxxx.lcl'
Sep 18 08:20:59 xxxxx NetworkManager[595]: (eno16780032): DHCPv4 state changed bound -> bound
Sep 18 08:20:59 xxxxx dhclient[652]: bound to 10.21.x.x -- renewal in 1636 seconds.

Digging around on the net, I wasn’t able to find anyone that had my problem, however did find something similar. https://mail.gnome.org/archives/networkmanager-list/2015-June/msg00018.html It looks like the new NetworkManager and dhclient with a kernel module now resets the routing table, which of course drops all connections. I haven’t found a solution yet, but I want to avoid going back to static addresses.

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