8.4 vs. 9.x: 127.0.0.0/8

Hello all,

    We are noticing what appears to be a significant difference between
PostgreSQL 9.x and 8.4. Not having found documentation that would point
us in the direction of a good solution, I thought I’d post our issue here.

On CentOS 6 we have postgresql 8.4.20 and the following pg_hba.conf:

local samerole all        md5
host samerole all  127.0.0.200   255.255.255.255   pam
pamservice=postgresql_cpses
host samerole all  127.0.0.1   255.255.255.255   md5
local all postgres        md5
host all postgres  127.0.0.1   255.255.255.255   md5

So connections to 127.0.0.200 are handled by pam, connections to
127.0.0.1 are handled by md5.

If I run:
root@jason:/$ psql -h 127.0.0.200 -U pguser
Password for user pguser:
psql: FATAL:  PAM authentication failed for user "pguser"

You can see it tried to authenticate using PAM authentication.

On CentOS 7 we have postgresql 9.2.13 and the following pg_hba.conf:

local samerole all        md5
host samerole all  127.0.0.200   255.255.255.255   pam
pamservice=postgresql_cpses
host samerole all  127.0.0.1   255.255.255.255   md5
local all postgres        md5
host all postgres  127.0.0.1   255.255.255.255   md5

But, running the command above yields a different result:
root@i-0000764a [/usr/local/cpanel]# psql -h 127.0.0.200 -U pguser
Password for user pguser:
psql: FATAL:  password authentication failed for user "pguser"

It tried to use password auth instead of PAM. We think postgresql might
be seeing any 127.0.0.0/8 address as 127.0.0.1. Could you please shed
some light on the issue or point us in the right direction on how to
make the 9.2.13 configuration function as the 8.4.20 configuration does?

    Thank you!

-Felipe Gasper
Houston, TX