Posting just in case someone else has the same problem as me.
Problem description: trying to add a gateway outside IP subnet fails*:
*my IP configuration (OVH failover IP - according to OVH failover IP configuration guide):
IP address (failover IP): 53.X.Y.Z
netmask: 255.255.255.255
gateway: 147.A.B.254 [where 147.A.B.C is an address of your dedicated server]
When trying to add/modify above IP configuration:
using https://vcenter.my.domain:5480/#/ui/networking
results in "Unable to validate the specified IPv4 configuration."
using DCUI of vcenter server:
results in gateway not being saved at all
using "/opt/vmware/share/vami/vami_config_net" inside vcenter server (ssh connection)
results in gateway not being saved at all
RESOLUTION:
1. connect to vcenter server via ssh
2. vim /etc/systemd/network/10-eth0.network
modify the file as shown below:
[Match]
Name=eth0
[Address]
Address=53.X.Y.Z/32
Peer=147.A.B.254/32
LinkLocalAddressing=no
DHCP=no
[Route]
Gateway=147.A.B.254
Destination=0.0.0.0/0
3. save file [:wq <enter> for vim]
4. ifdown eth0 ; ifup eth0 <enter>
5. Configuration is successfully saved. You can check it using:
/opt/vmware/share/vami/vami_config_net
or
via DCUI
or
via vcenter server management (https://vcenter.my.domain:5480/#/ui/networking)
Do not attempt to change configuration through DCUI now - or it'll be overwritten (by no gateway at all).
