Get Subnet mask in Linux using bash

linux bash networking iproute
ValeriRangelov picture ValeriRangelov · Oct 15, 2015 · Viewed 48.3k times · Source

I am using bash to get the IP address of my machine with that script:

_MyGW="$( ip route get 8.8.8.8 | awk 'N=3 {print $N}' )"

And now I am trying to get the Subnet Mask in this type:

192.168.1.0/24

But I have no idea how can I do that.

Answer

vishal picture vishal · Oct 15, 2015

there are couple of ways to achieve this:

first: to print the mask in format 255.255.255.0, you can use this:

/sbin/ifconfig wlan0 | awk '/Mask:/{ print $4;} '

second: we can use ip command to get the mask in format 192.168.1.1/24

ip -o -f inet addr show | awk '/scope global/ {print $4}'

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