You should find what you are looking for in Unisphere. Select the array, then select Network Settings under Settings from the top toolbar.
Hello  Our network team is changing our DNS servers. Most of what we have is IP based, but the host name entries for the SP are in our DNS servers as well.   How do I update the DNS entries for block only VNX 5700 arrays?   Thanks in advance,  Admingirl
How to change DNS entry for block only arrays