After updating the network config & doing a stack update, the mac address that was associated with eth0 has ended up on eth1 & vice versa.

Issue

• We needed to update ip addresses on management interface on 3 VM's.

• Each of the 3 VM's have 2 interfaces (Management i/f & and an Application i/f.

• We also took the opportunity to update from rhel ver 3.10.0-1062.el7.x86_64 to

• After updating the network config & doing a stack update, the mac address that was originally associated with eth0, ended up on eth1 and the mac address that was originally on eth1, ended up on eth0.

• Also the output of openstack server list, shows the order of the network info has swapped order as well. See below that the 1st 3 vm's(vm01-03 which are in cluster MOD1) which were not part of the update, have 'net-1901' as the 1st network & 'net-1916' as 2nd network, however after the stack update & a poweroff/power on, the vms vm04-06(which are in cluster MOD2), now have 'net-1951' as their second entry & we could not ssh onto the server via the management interface as the rules for the 1951 vlan were associated with the incorrect nic interface.

• We were able to access servers vm04-06 after shutdown -r, after shutdown -h, followed by a openstack server start 'server id' the mac addresses got reversed :

| Name                             | Networks                                                                                                                                                                      
| vm01-az1             | net-1901=10.10.10.65; net-1916=10.10.11.244                                                                                                    |
| vm02-az2             | net-1901=10.10.10.66; net-1916=10.10.11.245                                                                                                    |
| vm03-az1             | net-1901=10.10.10.67; net-1916=10.10.11.246                                                                                                    |
| vm04-az2             | net-196610.10.12.244; net-1951=10.10.10.192                                                                                                   |
| vm05-az1             | net-196610.10.12.245; net-1951=10.10.10.193                                                                                                   |
| vm06-az2             | net-196610.10.12.246; net-1951=10.10.10.194