Hi It is very nice that Ina replied me about mtu help Now I am using ping to check but not sure it is my modem or DSL company issue? C:\Documents and Settings\derek>ping yahoo.com -f -l 1300 Pinging yahoo.com [98.137.149.56] with 1300 bytes of data: Packet needs to be fragmented but DF set. Packet needs to be fragmented but DF set. Packet needs to be fragmented but DF set. Packet needs to be fragmented but DF set. Ping statistics for 98.137.149.56: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), C:\Documents and Settings\derek>ping yahoo.com -f -l 1200 Pinging yahoo.com [98.137.149.56] with 1200 bytes of data: Reply from 98.137.149.56: bytes=1200 time=141ms TTL=55 Reply from 98.137.149.56: bytes=1200 time=141ms TTL=55 Reply from 98.137.149.56: bytes=1200 time=145ms TTL=55 Reply from 98.137.149.56: bytes=1200 time=141ms TTL=55 Ping statistics for 98.137.149.56: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 141ms, Maximum = 145ms, Average = 142ms Thank you for your help