systemd sysctl rp_filter conflicting with cilium

[vincentmli]

openEuler systemd-sysctl could overwrite cilium rp_filter and cause similar issue reported in in cilium/cilium#10645, use workaround below to solve the problem

cat /etc/sysctl.d/90-override.conf

net.ipv4.conf.default.rp_filter = 0 
net.ipv4.conf.*.rp_filter = 0 

[vincentmli]

since openEuler has rp_filter enabled

[root@openEuler ~]# grep -r 'rp_filter' /usr/lib/sysctl.d/
/usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.default.rp_filter = 2 
/usr/lib/sysctl.d/50-default.conf:net.ipv4.conf.*.rp_filter = 2 
/usr/lib/sysctl.d/50-default.conf:-net.ipv4.conf.all.rp_filter

I recommend also add net.ipv4.conf.all.log_martians=1 in /usr/lib/sysctl.d/50-default.conf to make it easier for network trouble shooting

[vincentmli]

probably openEuler should adopt centos rp_filter setting

#grep 'rp_filter' /usr/lib/sysctl.d/50-default.conf 
net.ipv4.conf.all.rp_filter = 1