if i add a ip address on my wifi hotspot interface with
ip a add 192.168.20.1/24 dev wlan1 (in a root shell), i then can't ping it (or connect to it in any way) from my laptop that is in the same hotspot network with ip 192.168.20.20.
with tcpdump on the phone i see, the icmp requests coming in from 192.168.20.20 to 192.168.20.1, but they are just ignored by the phone.
This led me to believe that it has to do with some kind of firewall so i tried on my phone:
iptables -I INPUT -i wlan1 -j ACCEPT
iptables -I OUTPUT -o wlan1 -j ACCEPT
iptables -I FORWARD -i wlan1 -o wlan1 -j ACCEPT
iptables -I INPUT -d 192.168.20.1 -j ACCEPT
But no luck.
Does anyone have any idea, what makes android just ignore traffic destined for ips added with the ip command?
(phone: Fairphone4 with Lineageos 20-20230625-NIGHTLY-FP4, android-version: 13)