Windows xp does not provide a way to change the mtu setting from within netsh. for that you can: follow the instructions in kb283165 - how to change the pppoe mtu size in windows xp; use dr. tcp (note: windows 2000/xp only) tested with windows xp service pack 3. see also. configure tcpip max transfer unit (mtu) size in vista; setting the mtu in. The manually set or configure mtu size will take precedence over the mtu that the network adapter detects dynamically. in windows vista and windows vista, mtu can be easily viewed or changed with the “netsh” command. to run the “netsh” command, user need so to open an elevated command prompt window as administrator.. How to: change and check windows mtu size as part of network troubleshooting, you may need to check or change the maximum transmission unit (mtu) on your windows machine network interface card. the mtu is the size of a network packet that can be communicated in a single network transmission..
This command sends a ping using a 1500 byte packet size (mtu). you can slowly decrease the packet size, in increments of 10 or so, until you stop getting fragmented packet results. if the packet is too large, you will get “packet needs to be fragmented but df is set.”. In the picture below, you can see that pinging google with a packet size of 1465 bytes causes the packet to fragment, however pinging google with a packet size of 1464 does not fragment the packet. therefore the optimum mtu for my windows 2008 r2 server heading out to the internet is 1464.. Begin increasing the packet size from this number in small increments until you find the largest size that does not fragment. add 28 to that number (ip/icmp headers) to get the optimal mtu setting. for example, if the largest packet size from ping tests is 1462, add 28 to 1462 to get a total of 1490 which is the optimal mtu setting..
