An MTU limit that is set too high can cause fragmented packets and packet loss on your connection. This tutorial will explain how to test if your MTU limit is sending fragmented packets and will explain how to find what value you should be using.
1) Open an elevated command prompt and type:
netsh interface ipv4 show subinterfaces
and hit Enter.
You should get a list of all your network adapters installed on your PC. The MTU value is listed on the left.
All PPP connections (Point-to-Point Protocol) have a default MTU size of 1500 bytes and VPN connections have a defualt size of 1400. 28 bytes of this number is reserved for IP/ICMP overhead, so the effective MTU size here is 1472 (1500-28).
To work out if this MTU is too high for your connection, you need to ping with this amount of bytes. The best way to start is start with the default MTU and work your way down.
2) In an elevated command prompt, type the following to ping with an MTU size
ping google.com -f -l 1472
The -f marks packets that should not be fragmented in the ping. -l 1472 sets the size of the packet.
If you get successful replies, then your current MTU is fine for your connection. If you receive error messages like in the above image, then your packets are getting fragmented.
Keep trying to ping until you get 4 successful replies. Keep decreasing the MTU by 10, so if 1472 fails, try 1462.
You shouldn't go below 1400.
When you find a value that is successful, start to increase that value by 1, so if 1462 is successful, for example, try again with 1463 etc until you get errors again.
3) When you find a successful value, you can then set a new MTU limit with this value.
You will need to add 28 back on to the value for IP/ICMP overheads, so if 1462 is successful, then 1490 is your MTU limit.
To set your new limit, in an elevated command prompt use the following command
For a wired connection use:
netsh interface ipv4 set subinterface "Local Area Connection" mtu=1490 store=persistent
(You can change the interface name to whatever you're using. If you're connected via "Local Area Connection 2" then use this instead and so on)
For a wireless connection use:
netsh interface ipv4 set subinterface "Wireless Network Connection" mtu=1490 store=persistent
Change the MTU value to whatever value you found yourself. Remember you need to add 28 on to the value you were using in your pings. So if you were using a value of 1460 to ping, add 28 on, and the MTU value to set in the above commands will be 1488.
Simply hit Enter and the MTU value will be set.
Restart your PC for the changes to be effective.
If your router also has an MTU value that can be set, such as Netgear routers can have an MTU value set in the WAN settings, then you can add your value here as well.
I've done these steps myself, and it did infact help connections in some online games where I was getting packet loss. After doing these, I now get 0% packet loss. Web browsing is also a lot smoother on my wireless network with this tweak.
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Very interresting...i mean the command...I done the ping and got the value 1464 then add 28 and got the original value i did settle since i've got XP = 1492...(the normal setting!)
Thank you it had confirm my first ping parameter i'd set online, few years ago with an optimizer tool.
What's about Default TTL in Windows 7... 64 or 128 in decimal?
Computer type PC/Desktop System Manufacturer/Model Number [May-Dec-2012] - New Mid-tower - (is done!) OS Windows 7 Professional SP1 - x64 CPU Ivy Bridge Core i5 K Motherboard Asus H77 Chipset (ATX) Memory G.Skill DDR3 PC3-12800 (16Gb) Graphics Card Sapphire HD 7770 Vapor-X Oc Sound Card SBXi-Fi Xtreme Audio (w/5.1 sound system) Monitor(s) Displays Asus Led 21,5" Screen Resolution 16/9
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System Manufacturer/Model Number mickey megabyte 1234 OS ultimate 64 sp1 CPU i5 2500K 3.3@4.2GHz Motherboard MSI P67A-GD53 Memory 8 gigs GSkill Ripjaws 1600 Graphics Card amd hd6950 Sound Card creative x-fi gamer Monitor(s) Displays samsung 24" Screen Resolution 1920x1080
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Very interresting...i mean the command...I done the ping and got the value 1464 then add 28 and got the original value i did settle since i've got XP = 1492...(the normal setting!)
Thank you it had confirm my first ping parameter i'd set online, few years ago with an optimizer tool.
What's about Default TTL in Windows 7... 64 or 128 in decimal?
You don't need to change the TTL. That's the Time To Live and sets how long it takes a connection to timeout, in this case the ping. If you increase it then it takes longer to time out, and quicker to time out if you lower it.
Quote: Originally Posted by mickey megabyte
thanks Everlong,
tried it and 1462\1490 was my magic number.
i wonder if this will improve my kdr in bf2bc?
now why can't the OS do this itself?
I haven't tried BC2 since setting mine, but CSS certainly played smoother as well. Don't know why Windows sets such a high value though.
System Manufacturer/Model Number Custom Built OS Windows 7 Professional x64 Service Pack 1 CPU Intel Core i7 920 3.2GHz Motherboard ASUS Sabertooth x58 Memory 6GB XMS3 Corsair 1333MHz Graphics Card Zotac Nvidia Geforce GTX470 Sound Card ASUS Xonar DX/XD 7.1 Monitor(s) Displays Dell 24" S2409W + Dell 20" E207WFP Screen Resolution 1920x1080 + 1680x1050
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System Manufacturer/Model Number Custom Hack job OS Windows 7 Ultimate 64 bit CPU Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz Motherboard GigaByte EP45-UD3 Memory 8 GB Kingston Graphics Card Nvidia GeForce 9600GT Sound Card Soundblaster Audigy Monitor(s) Displays AOC x2 22"
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1 x Samsung 500GB Internet Speed 320 Other Info Winfast PVR2000CP
LG DVD-RAM DVD/RW/DL Super Multi
Linksys WMP300Nx2 Wireless Adapter
Very interresting...i mean the command...I done the ping and got the value 1464 then add 28 and got the original value i did settle since i've got XP = 1492...(the normal setting!)
Thank you it had confirm my first ping parameter i'd set online, few years ago with an optimizer tool.
What's about Default TTL in Windows 7... 64 or 128 in decimal?
Quote:
You don't need to change the TTL. That's the Time To Live and sets how long it takes a connection to timeout, in this case the ping. If you increase it then it takes longer to time out, and quicker to time out if you lower it.
Humm, well it is always on 64 decimal on my computers. tried 128 on 7 didn't much changes. Got that TCP Optimizer and created a .reg with it so i wouldn't bother recreate each time...so that why it is always set. Thanks anyway!
Computer type PC/Desktop System Manufacturer/Model Number [May-Dec-2012] - New Mid-tower - (is done!) OS Windows 7 Professional SP1 - x64 CPU Ivy Bridge Core i5 K Motherboard Asus H77 Chipset (ATX) Memory G.Skill DDR3 PC3-12800 (16Gb) Graphics Card Sapphire HD 7770 Vapor-X Oc Sound Card SBXi-Fi Xtreme Audio (w/5.1 sound system) Monitor(s) Displays Asus Led 21,5" Screen Resolution 16/9
Keyboard Razer + Razer gamepad Mouse Razer PSU 700w 80+ Gold (ErP 6 ready) Case Cooler Master Silencio 550-v2 (modded) Cooling Gelid Solutions (PWM Push/pull Fans) Hard Drives Internal:
500Go Sata 6Gb/s (x2)
500Go Sata 3Gb/s (x2)
SSD 60Go Sata 6Gb/s Antivirus MSE 4.2 Browser IE10 Rtm
System Manufacturer/Model Number Custom Built OS Windows 7 Professional x64 Service Pack 1 CPU Intel Core i7 920 3.2GHz Motherboard ASUS Sabertooth x58 Memory 6GB XMS3 Corsair 1333MHz Graphics Card Zotac Nvidia Geforce GTX470 Sound Card ASUS Xonar DX/XD 7.1 Monitor(s) Displays Dell 24" S2409W + Dell 20" E207WFP Screen Resolution 1920x1080 + 1680x1050
Keyboard Logitech G11 Keyboard Mouse Logitech G5 Laser Mouse (2007 edition) PSU Corsair HX850 modular Case Coolermaster 690II Advanced Nvidia Edition Cooling Corsair H60 Hard Drives 1x 120GB OCZ Vertex 2E, 1x 750GB Western Digital Caviar Black, 1x 1TB Western Digital Caviar Green Internet Speed 16Mbps Other Info LG Blu-Ray player
Computer type PC/Desktop System Manufacturer/Model Number Alienware Aurora ALX R4 OS Windows 7 x64 (SP1) CPU Intel Core i7-3930K (3.2GHz, Turbo 4GHz) Motherboard Alienware Aurora-R4 x79 Memory 4x Samsung 4GB PC3-12800 DDR3 (16GB 1600MHz) Graphics Card Nvidia Geforce GTX 690 (Stock) Sound Card RealTek Integrated Audio Monitor(s) Displays Dell UltraSharp U3011 Screen Resolution 2560x1600
PSU 875W Some Dell PSU <.< Hard Drives Samsung P830 256 GB, WD Raptor 150GB, 2x 1TB HDDs Other Info Dell Inspiron Mini 10v (Intel Atom N270 1.6 GHz; 1GB; Windows 7 Ultimate)
System Manufacturer/Model Number Gateway/NV7923u & NV79C52u Laptops OS windows 7 professional & ultimate 64bit laptops CPU 2.27 boost to 2.53 & 2.53 boost to 2.80 Motherboard Mobile Intel® HM55 Express Chipset ??? Memory 4GB Graphics Card Intel® Graphics Media Accelerator HD Sound Card realtek High-definition audio support Monitor(s) Displays 17.3 " HD 1600 x 900
Hard Drives hatachi Travelstar 5400 500GB & west digital 500GB Internet Speed 35MB fios
System Manufacturer/Model Number Custom Built OS Windows 7 Professional x64 Service Pack 1 CPU Intel Core i7 920 3.2GHz Motherboard ASUS Sabertooth x58 Memory 6GB XMS3 Corsair 1333MHz Graphics Card Zotac Nvidia Geforce GTX470 Sound Card ASUS Xonar DX/XD 7.1 Monitor(s) Displays Dell 24" S2409W + Dell 20" E207WFP Screen Resolution 1920x1080 + 1680x1050
Keyboard Logitech G11 Keyboard Mouse Logitech G5 Laser Mouse (2007 edition) PSU Corsair HX850 modular Case Coolermaster 690II Advanced Nvidia Edition Cooling Corsair H60 Hard Drives 1x 120GB OCZ Vertex 2E, 1x 750GB Western Digital Caviar Black, 1x 1TB Western Digital Caviar Green Internet Speed 16Mbps Other Info LG Blu-Ray player
Quote: Originally Posted by NoN 
