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Thread: meaning of CIDR mask in pg_hba.conf

meaning of CIDR mask in pg_hba.conf

From
Atul Kumar
Date:
Hi,

I have postgres version 12 running on centos 7.

I found an entry in my pg_hba.conf entry as given below under IPV4 connections:

host   all   all  <remote_ip>/0  md5

I could not understand the meaning of "/0" here.

as I know that each IPV4 there are total 4 octets and each octet will be read based on given CIDR mask (/8, /16, /24 or /32) but  I am watching first time "/0" that I couldn't understand, So please help me in explaining its prompt meaning and how IP will be read with /0?



Regards,
Atul

Re: meaning of CIDR mask in pg_hba.conf

From
"Steve Pointer"
Date:
> So please help me in explaining its prompt meaning and how IP will be read with /0?

It means no subnet mask so it will match all IP addresses.

Re: meaning of CIDR mask in pg_hba.conf

From
Adrian Klaver
Date:


On 10/30/23 10:45 AM, Atul Kumar wrote:
Hi,

I have postgres version 12 running on centos 7.

I found an entry in my pg_hba.conf entry as given below under IPV4 connections:

host   all   all  <remote_ip>/0  md5

I could not understand the meaning of "/0" here.

as I know that each IPV4 there are total 4 octets and each octet will be read based on given CIDR mask (/8, /16, /24 or /32) but  I am watching first time "/0" that I couldn't understand, So please help me in explaining its prompt meaning and how IP will be read with /0?


From here:


https://www.postgresql.org/docs/current/auth-pg-hba-conf.html


... 0.0.0.0/0 represents all IPv4 addresses, and ::0/0 represents all IPv6 addresses.


Is <remote_ip>/ one of the above?




Regards,
Atul