Question : When I ping 192.168.1.4 I get reply from 192.168.1.127

Hello all,

I may have 2 issues in this same question but I will let you decide that.

I have an issue at a customer, when I ping 192.168.1.4 I get:
C:\Users\Marklar>ping 192.168.1.4

Pinging 192.168.1.4 with 32 bytes of data:
Reply from 192.168.1.127: Destination host unreachable.
Reply from 192.168.1.127: Destination host unreachable.
Reply from 192.168.1.127: Destination host unreachable.
Reply from 192.168.1.127: Destination host unreachable.

What is causing this and how to I resolve it?

The customer is also having trouble staying online, every few minutes the internet goes down. When I try ping 4.2.2.2 it says request timed out but then it comes back up and works for a while longer. I am not sure that these issues are related because I gave my laptop their external IP address settings and plugged directly into their ADTRAN unit (they have a T1) when I try ping everything works fine but as soon as I download a file (i tested with a file about 80MB) I begin to get request timed out. This is just with my one laptop connecting to the T1 downloading one file. I called the ISP, they cannot see anything wrong with the connection when I told them about my test they said it is normal to drop some packets and it is TCP/IP's job to handle that.

Help is greatly appreciated.

Answer : When I ping 192.168.1.4 I get reply from 192.168.1.127

Download mturoute from http://www.elifulkerson.com/projects/mturoute.php, and start a

mturoute -t 4.2.2.2

This will check for the Path MTU, and where (if) it is reduced. MTU/fragmentation issues are often leading to massive packet drops, in particular in combination with VPN client software.