RedHat 7: SIOCDELRT: No such process

[user@telco-aa1]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         gateway         0.0.0.0         UG    100    0        0 ens192
10.15.55.0      0.0.0.0         255.255.255.0   U     100    0        0 ens256
new-dc1         10.120.88.1     255.255.255.255 UGH   100    0        0 ens161
10.120.88.0     0.0.0.0         255.255.248.0   U     100    0        0 ens161
10.120.100.0    0.0.0.0         255.255.255.0   U     100    0        0 ens192
192.168.202.0   0.0.0.0         255.255.255.0   U     100    0        0 ens224
[user@telco-aa1]#


[user@telco-aa1]# route del 10.120.100.0 ens192
SIOCDELRT: No such process
[user@telco-aa1]#

[user@telco-aa1]# ip r s
default via 10.120.100.1 dev ens192  proto static  metric 100
10.15.55.0/24 dev ens256  proto kernel  scope link  src 10.15.55.245  metric 100
10.120.0.13 via 10.120.88.1 dev ens161  proto dhcp  metric 100
10.120.88.0/21 dev ens161  proto kernel  scope link  src 10.120.94.93  metric 100
10.120.100.0/24 dev ens192  proto kernel  scope link  src 10.120.100.132  metric 100
192.168.202.0/24 dev ens224  proto kernel  scope link  src 192.168.202.245  metric 100
[user@telco-aa1]#

I am trying to delete the route 10.120.100.0 on interface ens192 but get the error: SIOCDELRT: No such process

Can anyone tell me how to delete this route?

This route to network 10.120.100.0/24 is not a static route (one that you configure), but it's there because your interface ens192 has an IP configured in that subnet (10.120.100.132 it seems.)

In order to get rid of that route, you would need to remove the IP 10.120.100.132 from interface ens192.

It's unclear why you would want to do that, considering your default gateway (10.120.100.1) seems to be using that ens192 interface on that network 10.120.100.132...