PDO PHP connection timeout but tsql commandline connect works

Question

Suddenly I have started experiencing a connection timeout 100% of the time from my local environment when using PDO in PHP for SQL Server.

This started happening without any changes to pdo config or server config. The error I am getting is :

PHP Fatal error:  500 SQLSTATE[HY000] [2002] Connection timed out #0 [internal function]: PDO->__construct

• connection works fine from different server with same config
• connection works fine when connecting through telnet on port 1433, so the port is open:

[root@webserver]# telnet xx.xx.xx.xx 1433

Trying xx.xx.xx.xx...

Connected to xx.xx.xx.xx.

Escape character is '^]'.

• connection works fine with tsql from command line and I can successfully run queries:

[root@webserver]# TDSVER=7.1 tsql -H xx.xx.xx.xx -p 1433 -U [user] -P [pass]

locale is "en_US.UTF-8"

locale charset is "UTF-8"

using default charset "UTF-8"

1>

• my configuration looks like this, and it has not changed since it last worked (or ever for that matter):

$connection = new \Db\Adapter\Pdo\MsSql(array(

           'host' => $config->mssql->host,
           'username' => $config->mssql->username,
           'password' => $config->mssql->password,
           'dbname' => $config->mssql->dbname,
           'pdoType'  => $config->mssql->pdoType,
           'dialectClass' => $config->mssql->dialectClass,
           'port' => 1433
       ));