the range 192.168.38.0 - 192.168.46.254 is not a /21 network.
The closest /21 networks are
192.168.32.0/21
(192.168.32.0 - 192.168.39.255)
192.168.40.0/21
(192.168.40.0 - 192.168.47.255)
Obviously you have the 192.168.32.0/24
network configured on a vlan interface.
When you set ip address 192.168.38.1 255.255.248.0
on another interface you get an error because you are actually adding the 192.168.32.0/21
network and this conflict with 192.168.32.0/24
which is a subnet of 192.168.32.0/21
You cannot chose an arbitrary range of IP address and declare that this range is a network. When you work with the IP address in binary form you can see why.
See this answer: How do you calculate the prefix, network, subnet, and host numbers? for more details
/24
, i.e. does it assign upwards or downwards? – dthree Apr 21 '17 at 19:04