IfInfo is a freeware networking utility for Nokia S60 3rd Edition mobile devices that allows you to determine and display various details about your WiFi WLAN or 3G/GPRS Internet Network interface such as:

Interface Name
State
Speed Metric
Mac Address
IP Address
Netmask
Broadcast
Gateway
DNS servers

Download here

Note: According to the comments on the website, some details such as Subnet Mask and Gateway is displayed incorrectly as 0.0.0.0 even for a working connection.