SDC registering with 3 IPs on network interface

Hi all!

I'm currently testing ScaleIO version R2_0.14000.231 and have found an issue.

I have a 5-node MDM cluster, which is running on RHEL 6.6 with 2.6.32-504.3.3.el6.x86_64 kernel.

MDM traffic goes through interface with two IPs:

• first for ScaleIO purposes (172.24.30.0/24),
• second for another service (192.168.128.0/24),

Also Master MDM gives additional (3rd) IP - ScaleIO cluster Virtual IP (172.24.30.100).

Here how it is:

6: eth1: 
  
    mtu 65520 qdisc noqueue state UP 
  
    link/infiniband a0:04:02:20:fe:80:00:00:00:00:00:00:f4:52:14:03:00:7b:06:91 brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
    inet 192.168.128.10/24 brd 192.168.128.255 scope global eth1
    inet 172.24.30.10/24 brd 172.24.30.255 scope global eth1
    inet 172.24.30.100/24 brd 172.24.30.255 scope global secondary eth1:mdm

When I tried to register these nodes as SDCs by adding MDM IP in /bin/emc/scaleio/drv_cfg.txt and start scini service I had the next issue:

• If I do it on Slave or Tie-breaker MDM (where only 2 IPs), I have no issues, SDC registers IP from ScaleIO subnet (172.24.30.0/24),
• But if I do it on Master MDM (with 3 IPs) SDC registers his IP from subnet 192.168.128.0/24

On CentOS 7.2 with 3.10.0-327.62.4.el7.x86_64 kernel there is no such issue.

And if I change the order of IP addresses in ifcfg-eth1 config, it works fine:

IPADDR2=192.168.128.10
PREFIX2=24

IPADDR1=172.24.30.10
PREFIX1=24

192.168.128.0/24 was IPADDR1.

What is the algorithm to determine IP address on interface to register as SDC or how can I select proper IP on it without change the order in config?