Setting up postgresql server connection with pgadmin3 fails with Exception

Question

I have installed postgresql database on Fedora 17.

When I create a new server connection through pgadmin3, I get this Error in a popup window:

postgresql The server doesn't accept the current user: The server report
Ident authentication failed
The server doesn't accept the current user: The server reports 

FATAL: Ident authentication failed for user "pgadmin" 
If this message appears, the pg_hba.conf entry found for your 
client / user / database combination is set to "ident" authentication.  
Some distributions, e.g. Debian, have this by default. To perform ident  
based authentication successfully, you need additional setup; see the  
PostgreSQL help for this. For a beginner, it might be more appropriate  
to use a different authentication method; MD5 encrypted passwords are  
a good choice, which can be configured by an entry in pg_hba.conf like  
this: 

host all all 192.168.0.0/24 md5 

This example grants MD5 encrypted password access to all databases to  
all users on the private network 192.168.0.0/24. 
You can use the pg_hba.conf editor that is built into pgAdmin III to  
edit the pg_hba.conf configuration file. After changing pg_hba.conf,  
you need to trigger a server configuration reload using pg_ctl or by  
stopping and restarting the server process. 

I have made the change mentioned in the error message, I added host all all 192.168.0.0/24 md5 to the pg_hba.conf. But I still get the same error. What am I doing wrong?

Solution

The mistake I made was that I forgot to uncomment the other lines that set the host, and I didn't restart postgresql so that new changes to that file would take effect. Here are the steps I used:

1. Find your pg_hba.conf, mine is in /var/lib/pgsql/data/pg_hba.conf

2. Here are the original incorrect contents of pg_hba.conf, notice the two host lines for IPv4 and IPv6:

   # TYPE  DATABASE        USER            ADDRESS                 METHOD
   
   # "local" is for Unix domain socket connections only
   local   all             all                                     peer
   # IPv4 local connections:
   host    all             all             127.0.0.1/32            ident
   # IPv6 local connections:
   host    all             all             ::1/128                 ident
   # Allow replication connections from localhost, by a user with the
   # replication privilege.
   #local   replication     postgres                                peer
   #host    replication     postgres        127.0.0.1/32            ident
   #host    replication     postgres        ::1/128                 ident
   

3. I had to add these lines at the end of that file

   host all all 127.0.0.1/32 md5
   #the 32 means only the first 32 bits cannnot change, not the first 24.
   #I use 32 because only one address will be accessing this server.
   

4. If you don't comment out the other default lines here it won't work:

   #host    all             all             127.0.0.1/32            ident
   # IPv6 local connections:
   #host    all             all             ::1/128                 ident
   

5. Then restart postgresql.

   [root@rosewill samples ]$ systemctl restart postgresql.service
   

After restart, try again, and the error is fixed. Then I can login to the sever with pgadmin3.