we have four DNS servers.
nsnt4.cissltd.com is on a separate ISP than the first three. Yesterday we shut off the nsnt2.cissltd.com and nsnt3.cissltd.com servers to rebuild a failed raid array. when the servers were off our DNS lookups failed and all of web hosting services were unavailable. Not good. Can anyone provide an answer as to why our DNS search order isn't working?
nsnt2.cissltd.com is the primary DNS server, the other DNS servers are all secondary.