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[Oldjim]

Sorry for starting a thread on such a mundane topic but I am confused 
My router Billion 8800NL has the MTU set at 1492 by default and that isn't a problem
What is a problem is what I should set the MTU on my PC's to 1492 or 1500

[NewtronStar]

Sorry for starting a thread on such a mundane topic but I am confused 
My router Billion 8800NL has the MTU set at 1492 by default and that isn't a problem
What is a problem is what I should set the MTU on my PC's to 1492 or 1500

The Billion 8800NL MTU is 1492 + 8 = 1500 so no need to change any MTU settings

[Oldjim]

So should the MTU on the PC be 1500 - if so I will need to change it

[Chrysalis]

1492 for pc's.  Or leave as auto configured. Dont set to 1500 (so if auto has set 1500 then overide with 1492),

[NewtronStar]

My Router shows MTU as 1492 and the PC shows as 1500

Microsoft Windows [Version 6.0.6002]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Windows\system32>netsh interface ipv4 show subinterfaces

   MTU  MediaSenseState   Bytes In  Bytes Out  Interface
------  ---------------  ---------  ---------  -------------
4294967295                1          0      25359  Loopback Pseudo-Interface 1
  1500                1  273048073   49331163  Local Area Connection


C:\Windows\system32>

[Oldjim]

so does mine now that I changed it 

[Chrysalis]

yes and your pc will be auto negotiating lower mtu's which probably adds a touch of delay when establishing connections.

think of your router as a 4 inch wide pipe, and your pc as a 4.2 inch block trying to shove through the pipe, the block has to be chopped up to fit.

want some hard evidence?

load up speedguide.net, goto analyzer and choose tcp analyzer, it should report a 1492 mtu.

[NewtronStar]

so does mine now that I changed it 

you can change it by using netsh interface ipv4 set subinterface "Local Area Connection" mtu=1492 store=persistent

But i can't feel any difference be it 1500 or 1492 

[Oldjim]

that is how I did it except for some reason it is Local Network 2

[NewtronStar]

load up speedguide.net, goto analyzer and choose tcp analyzer, it should report a 1492 mtu.

I did and get this stuff which i don't understand

[underzone]

I ran the v4.0.0 beta this from that site:

http://www.speedguide.net/downloads.php

Nothing seems worse... 

[Chrysalis]

its saying 1492 is optimsied for pppoe, and you are using pppoe, hence me saying set it to 1492

I actually usually overide the old fashioned way in the registry instead.

Now I am on sky tho I dont need to worry about this as sky doesnt use pppoe.

[NewtronStar]

Now I am on sky tho I dont need to worry about this as sky doesnt use pppoe.

Whats it called Sky MER OR just DHCP

[MikeZ]

I have my router PPPoE MTU set to 1500, which is supported by FTTC:

Code: [Select]

« SpeedGuide.net TCP Analyzer Results »
Tested on: 2015.07.17 05:15
IP address: 86.141.xxx.xxx
Client OS/browser: Windows 8.1 (Chrome 43.0.2357.134)
 
TCP options string: 020405b40103030801010402
MSS: 1460
MTU: 1500
TCP Window: 65536 (NOT multiple of MSS)
RWIN Scaling: 8 bits (2^8=256)
Unscaled RWIN : 256
Recommended RWINs: 64240, 128480, 256960, 513920, 1027840
BDP limit (200ms): 2621kbps (328KBytes/s)
BDP limit (500ms): 1049kbps (131KBytes/s)
MTU Discovery: ON
TTL: 113
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)


[Chrysalis]

mike I assume you using jumbo frames then.