Official forums for BZFlag.org

For those experiencing lag but are on DSL/Cable lines and still wondering why is my lag still high? Are you using a DLink router? I may have the solution for you.

For some reason, DLink (I still perfer their routers) has the MTU setting at 1500 by default. I dont know much of what MTU means but all I know is that if left at 1500, some secure sites dont work and I'm laggy on all BZflag servers. So this is what you do.

1) Access your router though your browser. For example mine is at 128.64.0.1
2) Under the "Home" tab, click the "WAN" page.
3) Where it says MTU, change that to 1492.
4) Click "Apply" and watch your lag mysteries go away.

Its that easy. Hopefully this helps other DLink router own3rs.

Hmmm... that's weird my default MTU setting is 1492. Have a D-Link DI-604 router.

I wish my router would just plain 'ol work, though! It won't give any IPs out except to my Mac totally keeping them off the Internet!!

A Meteorite wrote:Hmmm... that's weird my default MTU setting is 1492. Have a D-Link DI-604 router.

Try upgrading the firmware. Yea, mine is the wireless DI-624.

I use the DI-604 (nonwireless) and the default MTU value is 1492.
Something different won't work. (My DSL-Connection is powered by Arcor)

But i read, that you can decrease the MTU to 800 or so, just for playing.
But if you want to visit websites, you've to increase the MTU to 1492 again.

Here's a definition for MTU:

The Maximum Transmission Unit is the largest packet that a given network medium can carry. Ethernet, for example, has a fixed MTU of 1500 bytes, ATM has a fixed MTU of 48 bytes, and PPP has a negotiated MTU that is usually between 500 and 2000 bytes. (Note that ATM's 48-byte "cells" are at the extreme low level. Network stacks usually don't use the cells directly; instead, they run over a higher-level framing standard called AAL5, which has a 65536 byte MTU.)

How would turning it down give you better play? It doesn't seem logical.

It's logical:

At a high MTU, a packet needs more time to be sent.
So decreasing the MTU means, decreasing the neccesary time to send it.

You can compare with bottles of water:
2 small ones can be filled faster than one huge.

So the target recieves a continuos data stream excepting of big data blocks.

JPT is kinda right on that. Certain transmission mediums will send packets filling the entire MTU, even if the packet is smaller than that. So, even if you're only really trying to send and receive packets of, say for example, 700 or 800 bytes on such a line, it'll still burn off the full 1500 - 2000 byte space.

A Meteorite wrote:Hmmm... that's weird my default MTU setting is 1492. Have a D-Link DI-604 router.

I wish my router would just plain 'ol work, though! It won't give any IPs out except to my Mac totally keeping them off the Internet!!

i had that same exact router and i couldnt get it to work, it would work until i get a new ip then it would quit. nothing i could do wosuld help it. so i got my dad to buy a better linksys one

A Meteorite wrote:Hmmm... that's weird my default MTU setting is 1492. Have a D-Link DI-604 router.

I wish my router would just plain 'ol work, though! It won't give any IPs out except to my Mac totally keeping them off the Internet!!

oh and another thing have you been able to successfully port forward with this router

The reason the MTU is set to 1492 on DSL modems and routers is because of the 8 byte PPPOE overhead. Of course PPPOE is Point to Point Protocol Over Ethernet, hence the 1500 MTU for ethernet minus the 8 bytes for PPPOE. It's odd that it even logs you in properly with MTU set to 1500. Don't know much about DLink routers though...

A_Meteorite: What addresses is your router set to reserve for dhcp? Mine reserves 192.168.1.100 and up. You can set a static IP on the computers that don't work to anything below *.100, as long as they are each unique.

I have a D-Link DSL-604. I don't think there is a MTU setting. Is it possible to change it through telnet?

DSL users should also place their modem as close to the phone jack as possible, even if it's in another room or across the house, and use cat5e stp ethernet cable to run from your modem to computer. It will cut down on line noise and errors. I've had this problem recently and a new $20, 35 foot ethernet cable solved it.

Matt? wrote:

A Meteorite wrote:Hmmm... that's weird my default MTU setting is 1492. Have a D-Link DI-604 router.

I wish my router would just plain 'ol work, though! It won't give any IPs out except to my Mac totally keeping them off the Internet!!

oh and another thing have you been able to successfully port forward with this router

Sometimes it works, sometimes it doesn't.

TD-Linux wrote:A_Meteorite: What addresses is your router set to reserve for dhcp? Mine reserves 192.168.1.100 and up. You can set a static IP on the computers that don't work to anything below *.100, as long as they are each unique.

I have tried static DHCP. Anything I do won't work for my other computer. I think my network card in it is messed up... (but that doesn't explain why sometimes if I plug the ethernet cord in and out while booting it gets an IP address for a few hours)