Cannot create PoolableConnectionFactory

Hi all,
A PC on site is running ignition and is talking to a CompactLogix L33ER. It has been working perfectly until today. Somebody on site changed the IP address of the PC running the Scada. Once the IP had been changed back the OPC sever and Database connections had faulted.
I restated the OPC module and it now working OK and are communicating with the PLC just fine. However my SQL database connection is faulted and I’m not sure why??
The error message I’m getting is :
'Cannot create PoolableConnectionFactory (Commuinications Link failure The last packet sent to the server successfully was 0 milliseconds ago. The driver has not received any packets from the server.)

Any feedback is greatly appreciated!