[CentOS] C7, ipmi, NIC2, still fighting

[Chris Adams]

Once upon a time, mark <m.roth at 5-cent.us> said:
> This is that system with the missing management port, and I'm still
> fighting it. Everything *looks* right:
> 
> 3: enp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
> state UP group default qlen 1000
>     link/ether 00:25:90:0a:42:87 brd ff:ff:ff:ff:ff:ff
>     inet 192.168.0.100/24 brd 192.168.0.255 scope global enp6s0
> 
> ip route
> 192.168.0.0/24 dev enp6s0 proto kernel scope link src 192.168.0.100
> 
> and  ipmitool lan print
> IP Address Source       : Static Address
> IP Address              : 192.168.0.132
> Subnet Mask             : 255.255.255.0
> MAC Address             : 00:25:90:0a:42:92
> <...>
> Default Gateway IP      : 192.168.0.100
> Default Gateway MAC     : 00:25:90:0a:42:87

No, that does not look right.  You have configured the gateway of the
IPMI to be the host OS side of the NIC.  You can't do that... in a lot
of systems I've seen, the IPMI side of the NIC can't even talk to the
host OS on the network.

The IPMI LAN is an independent controller, separate from the host OS.
It does not use any routing/firewall/etc. from the host OS.  It is just
another device on the network that happens to share the same physical
port as the host.  It should be configured to talk to the same network
gateway and such as the host OS.

Think of it as if you have two independent systems inside one box; a PC
and an IPMI device.  It is similar to them being two devices with an
ethernet switch between them (and another port to the outside world).
It doesn't actually work that way (because they are sharing the physical
port), but it is close.
-- 
Chris Adams <linux at cmadams.net>