Jun 29, 2010 · So far we've shown you a number of ways you can configure your router. Another thing you can tweak in your router settings is the MTU time. We'll show you how to change your MTU time just in case

An appropriate MTU value is important to the proper operation of any network. To change the MTU on a DI series D-Link router, simply follow the steps below: 1. Connect to your router's admin interface. Usually 192.168.0.1. The default username is "admin" (without the quotes) and the default password is blank. 2. If you are using a DSL WAN connection: 1492. Sample layout of the command: $> ping –f –l (this is a lowercase “L”) [MTU size] [destination] How to check your LAN connection of your router to your computer: $> ping –f –l 1500 192.168.0.1. How to check your WAN connection from your carrier: This is my first experience with an 887VA router. I was surprised to see the ATM mtu is 1600. Is there anything I can do to speed this router's DSL performance? It is slower than an off the shelf ActionTec costing less than $100. I've already updated the firmware to the latest release. Same with IOS It is generally recommended that the MTU for a WAN interface connected to a PPPoE DSL network be 1492. In fact, with auto MTU discovery, 1492 is discovered to be the maximum allowed MTU. However, having an MTU of 1452 is most optimal. NOTE: To change the MTU size on the SonicWall UTM appliance refer to How to change the MTU size. In this case you would set MTU value on your modem to 1424. Note: OmniNet recommends using a value of 1424 but the above process will tell you the exact max MTU that your upstream network can carry. I have DSL and I want to set MTU to 1452, now what? Please contact the locations ISP support.

I am informed that MTU is standardized at 1500, but PPPoE reduces max MTU to 1492 due to its overhead and MSS should be set to 1452–that is the typical arrangement for DSL. My ISP, however, layers PPPoE on Ethernet, on ATM before it is layered on DSL (actually ADSL2+).

Hence, ICMP does not increase size of IP (that is already calculated in the “average” size of 20B). When calculating the MTU (section “Finding the MTU”), the number 8 is not actually from ICMP, but its from the PPPoE (which size is also variable due to different messages such as PADI, PADO etc., but 8 works as a “rule of thumb”).

The MTU an ISP uses will depend entirely on their setup, there is no "correct" answer. If your ISP is using static or routed IP's then a 1500 byte MTU can be set. If they're using PPPoE then the figure will vary but would typically be 1492 or 1480 depending on setup.

The Maximum Transmission Unit (MTU) feature of your Linksys router is an advanced configuration that allows you to determine the largest data size permitted on your connection. Generally, if your MTU is too large for the connection, your computer will experience packet loss or dropping internet connection.