Hello everyone
I am running into some strange issues when configuring networking interfaces on my physical server running Centos 7.5. Let me give you an overview of what's going on:
We have a physical server, running CentOS 7.5. This server has one 4 port NIC and one 2 port NIC and a Dell IDRAC port. The first port of the 4 port NIC, em1, is used for Management traffic. The first port of the 2 port NIC, is used for the second port in the NIC bond, device p6p2. The second port on the 4 port NIC, device em2 is the first, port on the NIC bond.
These interfaces are using Static IPs.
Here is my /etc/sysconfig/network-scripts/ifcfg-em1 file. Please keep in mind that I have changed the IPs and MAC addresses in the files for security reasons:
ifcfg-em1:
TYPE="Ethernet" PROXY_METHOD="none" BROWSER_ONLY="no" BOOTPROTO="none" 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="em1" UUID="bbb2f9c2-141b-4a99-ab1e-328551aae612" DEVICE="em1" ONBOOT="yes" IPADDR="192.168.56.50" PREFIX="24" GATEWAY="192.168.56.1" DNS1="192.168.126.10" DNS2="192.168.220.10" IPV6_PRIVACY="no" NM_CONTROLLED=no
as for the ifcfg-bond0 (the configuration file for the NIC bond, which is bond0):
DEVICE=bond0 NAME=bond0 TYPE=Bond ONBOOT=yes BOOTPROTO=none IPADDR=192.168.56.70 PREFIX=24 BONDING_MASTER=yes BONDING_OPT="mode=1 miimon=100" TYPE=Ethernet
and the ifcfg-slave1 configuration file, which is the first slave port for the NIC bond, this corresponds to em2:
DEVICE=em2 HWADDR="c8:2f:87:fg:2a:31" ONBOOT=yes TYPE=Ethernet BOOTPROTO=none MASTER=bond0 SLAVE=yes
and the ifcfg-slave2 configuration file , which corresponds to the second slave port for the NIC bond, which is interface p6p2:
DEVICE=p6p2 HWADDR="00:6a:d7:7c:e8:09" BOOTPROTO=none ONBOOT=yes TYPE=Ethernet MASTER=bond0 SLAVE=yes
I created a custom routing policy for the NIC bond, bond0. Here is the configuration for the routing policy:
route-bond0:
192.168.56.0/24 dev bond0 src 192.168.56.70 table t1 default via 192.168.56.1 dev bond0 table t1
and the rule-bond0 file:
table t1 from 192.168.56.70
as for the routing table:
Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.56.1 0.0.0.0 UG 0 0 0 bond0 192.168.56.0 0.0.0.0 255.255.255.0 U 0 0 0 bond0 192.168.56.0 0.0.0.0 255.255.255.0 U 0 0 0 em1 169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 em1 169.254.0.0 0.0.0.0 255.255.0.0 U 1008 0 0 bond0
now here is the scenario I am dealing with:
This linux server is used for monitoring purposes. We have Nagios, Cacti and other tools installed on it. There are a few things I have noticed and I want help on:
1) Whenever I ping any of the devices on our network, from this server, the traffic goes out from the management port. I do not want the traffic to go out of the management port. I want it to go out through the active port of the NIC bond. How do I configure the networking so that all primary network traffic flows to and from the NIC bonded interfaces? I only want the management port to be used for SSH purposes and well, management of the server.
2) I have configured the NIC bond in active-backup mode. I notice that when I used another computer to do a continuous ping to the NIC bond, and then I disable one of the slave interfaces of the bond, the ping drops and it does not failover to the backup slave interface and turn into the active one. It also causes any pings to the management port to drop as well. Then when I disable slave2, and enable slave1, the traffic does not fail over to slave1 and the ping continuously fails. It is only when I enable both slave interfaces and then either restart the networking using systemctl restart network, or reboot the server, the networking resumes and the pings succeed again. What steps should I take to fix this issue? Should I even use active-backup mode with the NIC bond or is there a better mode I should use?
3) Ive tested the networking, by changing the VLAN of the NIC bonded ports, on the switch, to a different VLAN, and it caused the management port to stop responding to ping. Why is this and how do I fix that if I decide to one day use two different VLANs for Management and the NIC bond ports?
Thank you for all of your help in advance!
Sean