Check your driver

inxi -Nn

My output in Lenovo R61

Network:
Device-1: Intel PRO/Wireless 3945ABG [Golan] Network driver: iwl3945
IF: wls3 state: up mac: 00:1f:3c:3b:71:c7
Device-2: Broadcom NetLink BCM5787M Gigabit Ethernet PCI Express
driver: tg3
IF: ens4 state: down mac: 00:1e:37:cb:5e:9d

The solution is to install kernel-ml

https://rhel.pkgs.org/8/elrepo-kernel-x86_64/kernel-ml-6.7.6-1.el8.elrepo.x86_64.rpm.html

Download latest elrepo-release rpm from
http://mirror.rackspace.com/elrepo/elrepo/el8/x86_64/RPMS/
Install elrepo-release rpm:
# rpm -Uvh elrepo-release*rpm
Install kernel-ml rpm package:
# dnf --enablerepo=elrepo-kernel install kernel-ml