MariaDB / MySQL galera cluster nodes won't join

I'm setting up a MariaDB Galera cluster and I can’t seem to get the nodes to join each other. They both start up without errors but never seem to join, the status is always disconnected:

MariaDB [(none)]> show status like 'wsrep%';
+--------------------------+----------------------+
| Variable_name            | Value                |
+--------------------------+----------------------+
| wsrep_cluster_conf_id    | 18446744073709551615 |
| wsrep_cluster_size       | 0                    |
| wsrep_cluster_state_uuid |                      |
| wsrep_cluster_status     | Disconnected         |
| wsrep_connected          | OFF                  |
| wsrep_local_index        | 18446744073709551615 |
| wsrep_provider_name      |                      |
| wsrep_provider_vendor    |                      |
| wsrep_provider_version   |                      |
| wsrep_ready              | ON                   |
+--------------------------+----------------------+

first node is started with: "sudo service mysql start —wsrep-new-cluster" (also tried passing in the cluster address just as —wsrep_cluster_address=gcomm://) as well as putting the empty address list in my.cnf

second node is started with: "sudo service mysql start" with cluster address in my.cnf as gcomm://172.16.56.130,172.16.56.131

no matter what the cluster status is always “Disconnected” and cluster size is 0.

I had some settings for SST to use xtrabackup, iptables firewall was on, etc but in order to try and find the issue I turned everything off and went with the most simple config & still the same result.

Here's the my.cnf

# MariaDB database server configuration file.

[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock


[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /var/lib/mysql
tmpdir      = /tmp
lc_messages_dir = /usr/share/mysql
lc_messages = en_US
skip-external-locking
bind-address        = 0.0.0.0

# * Fine Tuning
max_connections     = 100
connect_timeout     = 5
wait_timeout        = 600
max_allowed_packet  = 16M
thread_cache_size       = 128
sort_buffer_size    = 4M
bulk_insert_buffer_size = 16M
tmp_table_size      = 32M
max_heap_table_size = 32M


# * MyISAM
myisam_recover          = BACKUP
key_buffer_size     = 128M
table_open_cache    = 400
myisam_sort_buffer_size = 512M
concurrent_insert   = 2
read_buffer_size    = 2M
read_rnd_buffer_size    = 1M

# * Query Cache Configuration
query_cache_limit       = 128K
query_cache_size        = 64M
log_warnings        = 2
slow_query_log_file = /var/log/mysql/mariadb-slow.log
long_query_time = 10
log_slow_verbosity  = query_plan
log_bin         = /var/log/mysql/mariadb-bin
log_bin_index       = /var/log/mysql/mariadb-bin.index
expire_logs_days    = 10
max_binlog_size         = 100M

# * InnoDB
innodb_buffer_pool_size = 1G
#innodb_log_file_size = 100M
innodb_log_buffer_size  = 8M
innodb_file_per_table   = 1
innodb_open_files   = 400
innodb_io_capacity  = 400
innodb_flush_method = O_DIRECT


[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[mysql]

[isamchk]
key_buffer      = 16M


# MariaDB / Galera Cluster Settings
wsrep_provider         = /usr/lib/galera/libgalera_smm.so
wsrep_provider_options = "gcache.size=32G"
wsrep_cluster_address  = "gcomm://172.16.56.130,172.16.56.131"
wsrep_cluster_name     = 'my_galera_cluster'
wsrep_node_address     = '172.16.56.131'
wsrep_node_name        = 'lou-dev-sc-db2'
wsrep_sst_method       = xtrabackup
wsrep_sst_auth         = root:rootPa$$
wsrep_slave_threads    = 16

binlog_format                  = ROW
default_storage_engine         = InnoDB
innodb_autoinc_lock_mode       = 2
innodb_locks_unsafe_for_binlog = 1
innodb_flush_log_at_trx_commit = 2

# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
!includedir /etc/mysql/conf.d/

I also realize that the xtrabackup needs access rights made available so I have also made a GRANT entry for that user from the remote servers and tested via manual login, still no dice.

Any ideas?