We have a lan of 10 workstations ... Our router ip is 10.0.0.1 ...

I get the following error while installing zimbra on my machine....

DNS ERROR resolving leena //-->my hostname...
It is suggested that the hostname be resolveable via DNS
Re-Enter hostname [Yes] LEENA
A Yes/No answer is required
Re-Enter hostname [Yes] yes
Please enter the logical hostname for this host [leena] LEENA
No results returned for A lookup of LEENA
Checked nameservers:
10.0.0.1


DNS ERROR resolving LEENA
It is suggested that the hostname be resolveable via DNS

is it because my machine is not assigned a domain name or some thing of that sort.