Change PostgreSQL pg_hba.conf IPv6 local connection setting from ::1/128 to my own Temporary IPv6 Address doe not work

Question

My postgresql connection works if I stick to the following default set up:

# "local" is for Unix domain socket connections only
local   all             all                                     md5
# IPv4 local connections:
host    all             all             127.0.0.1/32            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5
# Allow replication connections from localhost, by a user with the
# replication privilege.
local   replication     all                                     md5
host    replication     all             127.0.0.1/32            md5
host    replication     all             ::1/128                 md5

Now I'm trying to allow another computer in the same household connecting to the current server, and am trying a few settings. One of the changes I made is to the IPv6 local connection line, is to use my Temporary IPv6 Address instead, because if I check what's my ip on google, that is the ip shown up there.

# IPv6 local connections:
host    all             all             1111:2222:a111:a11:b222:11a:abcd:efgs                md5

(Note the ip used here is just an example )

However, this would lead to the follow errors in postgresql log:

2021-11-21 12:26:40.508 PST [10356] LOG:  starting PostgreSQL 13.3, compiled by Visual C++ build 1914, 64-bit
2021-11-21 12:26:40.515 PST [10356] LOG:  listening on IPv6 address "::", port 5432
2021-11-21 12:26:40.517 PST [10356] LOG:  listening on IPv4 address "0.0.0.0", port 5432
2021-11-21 12:26:40.529 PST [10356] LOG:  invalid IP mask "md5": Unknown host
2021-11-21 12:26:40.529 PST [10356] CONTEXT:  line 88 of configuration file "C:/current_dir/PostgresSQL/data/pg_hba.conf"
2021-11-21 12:26:40.531 PST [10356] FATAL:  could not load pg_hba.conf
2021-11-21 12:26:40.533 PST [10356] LOG:  database system is shut down

What are the possible reasons causing this error please? Thank you very much.

Answer 1

You cannot specify a client IP address in pg_hba.conf , you have to specify a CIDR. Per the documentation :

An IP address range is specified using standard numeric notation for the range's starting address, then a slash ( / ) and a CIDR mask length. The mask length indicates the number of high-order bits of the client IP address that must match. Bits to the right of this should be zero in the given IP address. There must not be any white space between the IP address, the / , and the CIDR mask length.

So the entry would have to look like:

host  all  all  fe80::8b0a:b1bf:4ce5:9a4a/128  md5