How to fix slow network with Realtek RTL8188CE

Open Terminal and run

inxi -Nn

… if you see like

Network:
Device-1: Realtek RTL8188CE 802.11b/g/n WiFi Adapter driver: rtl8192ce
IF: wlan0 state: up mac: ac:81:12:cf:d6:5c
Device-2: Realtek RTL810xE PCI Express Fast Ethernet driver: r8169
IF: eth0 state: down mac: xx:xx:xx:xx:xx:xx

The fix is to make a /etc/modprobe.d/rtl8192ce.conf file as

options rtl8192ce ips=0 fwlps=0

The source: https://wiki.debian.org/rtl819x#rtl8192ce