[CentOS] Need help getting two NICs to work on CentOS 7

Mon Nov 7 07:00:24 UTC 2016
Sean Son <linuxmailinglistsemail at gmail.com>

Hello all

Here is the scenario:  We have a mail server VM which currently has two
virtual NICs attached to it. One NIC is has an IP on a subnet with a
default gateway defined and the other NIC has an IP on a different subnet
with a different gateway on a different VLAN defined. Now when I activate
both NICs, and run an ifconfig -a, I see that both IP addresses are
showing. Now here is the problem. When I ping the VM, the first NIC's IP is
not pingable at all, but the second NIC's IP is pingable. How do I
configure the networking so that both IPs are pingable and the VM is
reachable via both IPs? Please let me know what I may be doing wrong!

Thank you!