Just a quick note to share a problem encountered today on one of our
servers.

We have users that connect to an Informix database using an ODBC
connection and Microsoft products (Access, Excel, Query) to obtain
data.

Today, the PCs started giving these errors when connecting:

ERROR: -27004: S1000: [Informix][Informix ODBC Driver][Informix]Illegal
sqlhosts file option/parameter.

The problem turned out to be a failure by the PC to reach the Unix host
due to a failed DNS lookup. The ODBC connection was using the host
system name instead of its IP address. The DNS server had experienced a
problem the previous evening and was never reconfigured properly.

This was determined by pings done from the PC:

# ping 192.168.77.251
Pinging 192.168.77.251 with 32 bytes of data:

Reply from 192.168.77.251: bytes=32 time<10ms TTL=255
Reply from 192.168.77.251: bytes=32 time<10ms TTL=255
Reply from 192.168.77.251: bytes=32 time<10ms TTL=255
Reply from 192.168.77.251: bytes=32 time<10ms TTL=255

Ping statistics for 192.168.77.251:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms


# ping SampleSystem
Unable to resolve host entry, SampleSystem

So if your ODBC suddenly stops working and gives this error, this may
be something for you to test out. Hope it helps someone.