I opened a support case about this, but it just keeps going around in circles.
I recently attempted to download an OnTap update from our internal HTTP server for our AFF8040, and the address that the NetApp was coming in as is 172.22.19.23 which isn't assigned to anything that I can find on the filer. (The same exact thing is happening on our other cluster in a different data center with different IPs)
On the filer, e0M has a MAC address of “00:a0:98:a2:2f:b3”
Oriole::> network port show -node Oriole-01 -port e0M
Auto-Negotiation Administrative: true
Auto-Negotiation Operational: true
Duplex Mode Administrative: auto
Duplex Mode Operational: full
Speed Administrative: auto
Speed Operational: 1000
Flow Control Administrative: full
Flow Control Operational: full
MAC Address: 00:a0:98:a2:2f:b3
On the switch, there are a number of ARP entries all related to that MAC address on Port 2:11.
Destination Mac Age Static VLAN VID Port
172.22.16.5 00:a0:98:a2:2f:b3 7 NO Internal_Appliances 16 2:11
172.22.16.7 00:a0:98:a2:2f:b3 4 NO Internal_Appliances 16 2:11
172.22.19.23 00:a0:98:a2:2f:b3 1 NO Internal_Appliances 16 2:11
The first two addresses as statically assigned on the filer:
Oriole::> network interface show
Logical Status Network Current Current Is
Vserver Interface Admin/Oper Address/Mask Node Port Home
172.22.19.23 is clearly being sent by something on the NetApp side as that address is shown to have the same MAC address as 172.22.16.5, 172.22.16.7 (both of those IPs are assigned to e0m) but what is it?
When you perform a fresh installation of ONTAP 9.3, and the boot environment
variable "bootarg.init.dhcp.disableb is either undefined or set to "false", the
e0M management interface attempts to automatically obtain an IP address during
the boot process.
As a result, if the storage system can access a Dynamic Host Confiuration
Protocol (DHCP) server, the system obtains an additional IP address for the
e0M interface. This DHCP IP address might be removed during the cluster setup
process when configuring a static IP address. However, DHCP requests to obtain
IP addresses continue at every reboot and the DHCP IP address might again be
configured on the e0M interface when the reboot process completes. The
DHCP-assigned IP address remains active on the e0M interface until you set
the "bootarg.init.dhcp.disableb variable to "true" and the system is rebooted.