Largest MTU help.

btr1 · Post by **btr1** » Sun Sep 24, 2006 11:34 am

Hi, first post,

Need some help on finding the largest mtu

Pinging [xxxx] with 40 bytes ->bytes=40 time=21ms TTL=56
Pinging [xxx] with 750 bytes ->bytes=750 time=24ms TTL=56
Pinging [xxx] with 1125 bytes ->Request Timed Out
Pinging [xxx] with 1125 bytes ->Request Timed Out
Pinging [xxx] with 1125 bytes ->Request Timed Out
Couldn't determine largest possible MTU due to packets being lost.
You might want to try a different URL

No matter what IP i use or what site it allways time out with the 1125 bytes and says that it couldnt determine largest possible MTU due to packets being lost

Any fix or is 1125 my largest mtu?

thanks

trogers · Post by **trogers** » Sun Sep 24, 2006 12:09 pm

Do the TCP Analyzer test and post your results.

The "request timed out" may just be due to routers that do not respond to ICMP signals.

btr1 · Post by **btr1** » Sun Sep 24, 2006 12:13 pm

TCP options string = 020405b40103030301010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.
Default TCP Receive Window (RWIN) = 283240
RWIN Scaling (RFC1323) = 3 bits (scale factor of 6)
Unscaled TCP Receive Window = 35405

RWIN is a multiple of MSS
Other RWIN values that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)
bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 11329.6 kbps (1416.2 KBytes/s) @ 200ms
Your TCP Window limits you to: 4531.84 kbps (566.48 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 52 hops
TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000 (0)

--------
Is this what you need, I'm kinda new to tweakin

trogers · Post by **trogers** » Sun Sep 24, 2006 12:16 pm

Yes. Your largest MTU is 1500 as show in your test report. What speed did you pay your ISP to give you? Which country are you in?

btr1 · Post by **btr1** » Sun Sep 24, 2006 12:25 pm

I believe its 6 Mbps, not really sure i pay $ 49.99 per month for it.
From the U.S.

trogers · Post by **trogers** » Sun Sep 24, 2006 12:28 pm

Use the following custom setting with TCP Optimizer:

General Settings tab:
Custom settings - check
Modify All Network Adapters - check
network adapter selection - your NIC
MTU - 1500
TTL - 64
TCP Receive Window - 128480
MTU Discovery - Yes
Black Hole Detect - No
Selective Acks - Yes
Max Duplicate ACKs - 2
TCP 1323 Options:
Windows Scaling - checked
Timestamps - uncheck
Advanced Settings tab:
Max Connections per Server - 10
Max Connections per 1.0 Server - 20
LocalPriority - 5
Host Priority - 6
DNSPriority - 7
NetbtPriority - 8
Lan Browsing speedup - optimized
QoS: NonBestEffortLimit - 0
ToS: DisableUserTOSSetting - 0
ToS: DefaultTOSValue - 80
MaxNegativeCacheTtl - 0
NetFailureCacheTime - 0
NegativeSOACache Time - 0
LAN Request Buffer Size - 32768
Then select "Apply Changes" and reboot to take effect

btr1 · Post by **btr1** » Sun Sep 24, 2006 6:02 pm

by "mnosteele52"Under your LAN connection - properties - general tab, uninstall all the protocols there that you do not need. For a stand alone pc all you need is Internet Protocol TCP/IP.

I have these listed

"Client for Mircosoft networks"
"File and Printer sharing for micro networks"
"QoS Packet schedlur"
" Internet Protocol TCP/IP"

So im able to remove all but the " Internet Protocol TCP/IP"?

YARDofSTUF · Post by **YARDofSTUF** » Sun Sep 24, 2006 6:08 pm

No, you need the other stuff too. You see how the icon next to TCP/IP is different? thats the protocol icon, if you had more there then you could get rid of them, but you only have 1 protocol, so leave all that there.

EDIT: Trogers is right too, you can delete QoS if you wish.

trogers · Post by **trogers** » Sun Sep 24, 2006 6:09 pm

Yes, if you are using only one PC you need to keep only Internet Protocol TCP/IP.

If you are connecting more than one PC to a router and they share files and printer, then you need only to delete QoS.

btr1 · Post by **btr1** » Sun Sep 24, 2006 6:14 pm

ok i see. so if i had more then 1 Internet Protocol TCP/IP.? then uninstall them ,
I have no router or printer

Very basic setup, cable line to modem,modem to pc via Ethernet cable

trogers · Post by **trogers** » Sun Sep 24, 2006 6:17 pm

Do not delete the Internet Protocol TCP/IP!!! You need this to connect to the internet.

btr1 · Post by **btr1** » Sun Sep 24, 2006 6:19 pm

yea i kinda figure that one out, How about the rest of them? Im not sure if i need them or not

trogers · Post by **trogers** » Sun Sep 24, 2006 6:23 pm

Since you have only one PC, you do not have any networks, and so can delete

"Client for Mircosoft networks"
"File and Printer sharing for micro networks"

It is also a good practice to delete them to prevent hackers using remote control to access your files.