I do not understand genmask:
my netstat
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlo1
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 br0
10.42.0.0 0.0.0.0 255.255.255.0 U 0 0 0 cni0
10.121.173.0 0.0.0.0 255.255.255.0 U 0 0 0 mpqemubr0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 virbr0
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
I can ping docker0:
ping -c 4 172.17.0.1
PING 172.17.0.1 (172.17.0.1) 56(84) bytes of data.
64 bytes from 172.17.0.1: icmp_seq=1 ttl=64 time=0.062 ms
64 bytes from 172.17.0.1: icmp_seq=2 ttl=64 time=0.078 ms
64 bytes from 172.17.0.1: icmp_seq=3 ttl=64 time=0.082 ms
64 bytes from 172.17.0.1: icmp_seq=4 ttl=64 time=0.101 ms
--- 172.17.0.1 ping statistics ---
And also:
172.17.0.4
If I enter:
ping -c 4 172.17.0.4
PING 172.17.0.4 (172.17.0.4) 56(84) bytes of data.
From 172.17.0.1 icmp_seq=1 Destination Host Unreachable
From 172.17.0.1 icmp_seq=2 Destination Host Unreachable
From 172.17.0.1 icmp_seq=3 Destination Host Unreachable
From 172.17.0.1 icmp_seq=4 Destination Host Unreachable
--- 172.17.0.4 ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 3061ms
pipe 4
Why?
How does genmask defines host and network part?
