How renew ipv4 and ipv6 on bash

[Bytechanger]

Hi,

I‘ve problems on WAN and would to renew my ipv4 and ipv6 over bash.

But when I use

system dhclient restart vtnet0

It says, dhclient is aleeady running under pid….

When I try to stop  sudo service dhclient stop vtnet0
"vtnet0' is not a DHCP-enabled interface"

Hoe can I renew my ipadresses??

 ifconfig igb0 down

 ifconfig igb0 up

will stop traffic for a time, thats not good.

Greets