how can I Get IP Address from thin client which is using RDP for connection

I am using on thin client which is basically disk less node like HCL win bee and connect the windows server 2003 by using RDP Protocol. While working with vb.net 2005 following statments gives server ip not particular client ip.

strHostName = System.Net.Dns.GetHostName()
strIPAddress = System.Net.Dns.Resolve(strHostName).AddressList(0).ToString()

My question is how to get client IP with vb.net 2003 for client that uses RDP.

Thanks in advance