using grep to match ip quad

[aswolff]

I am trying to use grep to find ip addresses in a file. I've tried all sorts of variants but none work. Can somebody help?

grep \b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b IP.txt
grep '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}' IP.txt
grep "\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b" IP.txt
grep '172.30.218.123' IP.txt <===This works!
grep '\d72.30.218.123' IP.xt <===Does not work!

What am I missing...?

TIA

 

[PHV]

And what about this ?
grep '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' IP.txt

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[aswolff]

This ended up working:

grep '[0-9]\{1,3\}.[0-9]\{1,3\}.[0-9]\{1,3\}.[0-9]\{1,3\}' IP.txt


Thanks....