You have an IP Address and you want to ping it using your application you can use Ping class.
First of all import System.Net.NetworkInformation namespace
using System.Net.NetworkInformation;
Then use Send method of Ping class to ping an IP as shown below:
Ping ping = new Ping();
PingReply pingReply = ping.Send("181.121.149.37");
Console.WriteLine("Address: {0}", pingReply.Address);
Console.WriteLine("Time in miliseconds: {0}", pingReply.RoundtripTime);
Console.WriteLine("Status: {0}", pingReply.Status);