Page 1 of 2 12 LastLast
Results 1 to 20 of 24

Thread: Cannot Change MtU

  1. #1
    Junior Member
    Join Date
    Jun 2004
    Posts
    10

    Cannot Change MtU

    I cannot change my mtu. I used the analizyer alot of times but the mtu stays the same. I am on an XP SP1, I am on DSL PPPOE XP and i dled the XP PPPOE patch, i changed my router mtu to 1480 and in the tcp optimizer i also changed it to 1480 but it doesnt work. The MTU just stays the same. If you can help me out on this, it will be really appreciated.

    I also need optimal settings for my connection. SBC DSL 1500/128 PPPOE

    These are my stats.

    TCP options string = 0204052a01010402
    MTU = 1362
    MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput.
    MSS = 1322
    MSS is not fully optimized for broadband (although it might work well for slower connections). Consider increasing your MTU value.

    Default Receive Window (RWIN) = 64800
    RWIN Scaling (RFC1323) = 0 bits
    Unscaled Receive Window = 64800

    For optimum performance, consider changing RWIN to a multiple of MSS.
    Other values for RWIN that might work well with your current MTU/MSS:
    507648 (MSS x 48 * scale factor of 8)
    253824 (MSS x 48 * scale factor of 4)
    126912 (MSS x 48 * scale factor of 2)
    63456 (MSS x 48)
    bandwidth * delay product (Note this is not a speed test):

    Your RcvWindow limits you to: 2592 kbps (324 KBytes/s) @ 200ms
    Your RcvWindow limits you to: 1036.8 kbps (129.6 KBytes/s) @ 500ms
    MTU Discovery (RFC1191) = OFF
    Time to live left = 117 hops

    TTL value is ok.
    Timestamps (RFC1323) = OFF
    Selective Acknowledgements (RFC2018) = ON
    IP type of service field (RFC1349) = 00000000

    The MTU Stays like that.

  2. #2
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    what brand and make of modem you have ??
    Comptia a+ n+

  3. #3
    Junior Member
    Join Date
    Jun 2004
    Posts
    10

    cannot change mtu

    speedstream 5100

  4. #4
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    http://kb.efficient.com/utility/getfile.asp?rid=516 i would try that first you are going to need the acrobat reader to read that but i think that is ur fix and also try what's below










    Troubleshooting WWW Access over Shared PPPoE Connection you want 1492 also you could use the optimizer instead of dr tcp the optimizer is below me to download and install


    If you are using Windows' built-in support for Internet Connection Sharing, and your Internet connection is facilitated by PPPoE software (such as EnterNet 300) or Windows XP's built-in PPPoE, your client PCs may not be able to visit certain websites.



    The problem is caused by an incompatible MTU networking setting: the Windows default is 1500, but PPPoE uses 1492 or 1454. The following steps describe how to fix it manually.



    You can also use a third-party utility such as DrTCP if you would prefer a friendlier GUI and less typing. Please note that we do not support DrTCP or any third-party applications; this is provided only as a courtesy on the recommendation of a customer.



    Find the IP address of your gateway. If you are using Windows 2000 or XP, run IPCONFIG at a command prompt on the Host computer. If you are using Windows 98 or Me, run WINIPCFG on the Host computer. In both cases you should be presented an IP address.


    Next go to one of the client PCs and enter the following:

    PING -f -l 1500 xxx.xxx.xxx.xxx

    If you receive an error message indicating fragmentation enter the following:

    PING -f -l 1492 xxx.xxx.xxx.xxx

    If that does not work, try the other common MTU value:

    PING -f -l 1454 xxx.xxx.xxx.xxx

    The numbers in each of these examples (1500, 1492, 1454) are the most common MTU values.


    Configure all your client PCs to use the new, lower MTU as the default for all Internet communication.


    Configuring Client PCs Running Windows 98, 2000 or XP


    Run the Registry Editor (REGEDIT.EXE) on one of your client PCs.

    Note: You should always make a backup copy of your registry before editing it.


    Navigate to HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Services\ Tcpip\ Parameters\ Interfaces.


    There should be several subkeys under the [Interfaces] key; in most cases you will find three (3). Find the subkey which corresponds to your primary network adapter; it will be the one with the most values and will have an IP address value similar to [192.168.0.x].


    Once you've found the correct subkey create a new DWORD value within it [Edit > New > DWORD Value] and name the value [MTU].


    Double-click the new value, choose the [Decimal] option, and enter the MTU value determined above.


    Click [Ok] when you are done – you will need to restart Windows for this change take effect.


    7. Repeat for each Client machine.
    Comptia a+ n+

  5. #5
    try uninstall your tweaking file
    some tweaking can set the mtu

  6. #6
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    also change the router's mtu to 1492
    Comptia a+ n+

  7. #7
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    http://kb.efficient.com/utility/getfile.asp?rid=516

    I looked at the manual but i dont know what u want me to do with it and it is for 5260, i have 5100.

    i also did what u told me below and i changed back to my regular settings and did the pings and i set up the mtu. It pinged at 1470 and i changed the registry to 1470 and restarted computer, i pinged it again and it says it needs to be fragmented but DF set, Then the highest mtu it went up to was 1430. I changed it to 1430 and restarted and now it says that needs to be fragmented. I also changed the router back to 1492.

    When i analizyed it, the MTU stays the same 1362.

  8. #8
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    http://speedstream/ go login to your modem/router and put in bridge mode if it is in router mode it wiill porbably set the mtu not the othe roruter, then change mtu for router to 1492 if the xp cilent's show up as 1492/1480 your find http://kb.efficient.com/display/1/kb....asp?aid=46057

    Browse though those settings they might have an mtu setting in there so look around after you logged in.
    Comptia a+ n+

  9. #9
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    I read the article and it said that i cannot put it in bridged mode since it doesnt support PPPOE and it doesnt say anything about MTU.

    I also tried to put it in bridged mode and i couldnt even access the internet or the modem. I had to reset the modem and i changed it back to PPPOE location in the computer. Because i have a router too. I also want to know if u can access the modem if u hooked up the router because i had to switch ethernet cables directly from the modem to the computer so i can access the modem.

    On the modem it says i am connected at 1536/256

  10. #10
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    ithe router would take care of the login for you just enter your useername and passoword on the routers page what make and model of router you have..

    That's why i said bridge modem change mtu on router so that the router will chnage the mtu..
    Comptia a+ n+

  11. #11
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    Ok i bridged the connections and the connection works and i changed the router's mtu to 1492 but when i went to the analizyer, the mtu stays the same. 1362

  12. #12
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    http://www.dslreports.com/tweaks try this test and see if mtu changes i have a hutch on something
    Comptia a+ n+

  13. #13
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    IT doesnt change. I havent optimized my connection yet.
    here are the readouts:

    http://ttester.broadbandreports.com/...ia=routerpppoe


    Service: DSL
    Speed: 1500
    OP System: XP
    Connection: RouterPPPOE

    Your Tweakable Settings:
    Receive Window (RWIN): 65340
    Window Scaling: off
    Path MTU Discovery: OFF
    RFC1323 Window Scaling: OFF
    RFC1323 Time Stamping: OFF
    Selective Acks: ON
    MSS requested: 1322
    TTL: unknown
    TTL remaining: 120

    2. Test 146000 byte download
    Actual data bytes sent: 146000
    Actual data packets: 111
    Max packet sent (MTU): 1362
    Max packet recd (MTU): 1362
    Retransmitted data packets: 0
    sacks you sent: 0
    pushed data pkts: 5
    data transmit time: 0.891 secs
    our max idletime: 136.6 ms
    transfer rate: 78916 bytes/sec
    transfer rate: 631 kbits/sec
    This is not a speed test!
    transfer efficiency: 100%


    3. ICMP (ping) check
    arget unpingable

  14. #14
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    http://www.broadbandnuts.com/index.p...;threadid=2150 try this fix and see if mtu chnages.. i hope it now takes.
    Comptia a+ n+

  15. #15
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    IT doesnt, ive used that even before i posted

  16. #16
    SG Enthusiast
    Join Date
    Mar 2002
    Location
    Poland
    Posts
    1,107
    fixed router's MTU=1362 for PPPoE
    (but for plain TCP/IP =1440)
    look like 'a few routers' with build in VPN

    up to now I know only one advice
    change router - ask for recomendations
    BTW above does not change connection's speed

    or set OSregistry apropriate value(s) equal to router's - strongly recomended

  17. #17
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    http://dslnuts.com/pppoe/mtustuck.htm try installing rasspoe but remove your xp ppoe connection first and any other ppoe software and see if we could the mtu to 1492 so it would match the router.
    Comptia a+ n+

  18. #18
    fem the retarded rabbit mccoffee's Avatar
    Join Date
    Nov 2001
    Location
    Cleveland, Ohio, United States
    Posts
    13,365
    Andrzej what he is trying to say is login back in modem and see if there is any vpn vitural private networking settings if so disable them Also check the router ans see if the vpn is disabled there too
    Last edited by mccoffee; 06-23-04 at 02:15 PM.
    Comptia a+ n+

  19. #19
    SG Enthusiast
    Join Date
    Mar 2002
    Location
    Poland
    Posts
    1,107
    sory to say
    but in mentioned of routers
    no such options
    or are not active (eg MTU=1492 for PPPoE)

    IMO much better is optymize to actual value (1362).

    again
    BTW new 'home router' with MTU=1492 does NOT speed-up Internet connection.

  20. #20
    Junior Member
    Join Date
    Jun 2004
    Posts
    10
    I switched to raspppoe and it didnt do anything, i also looked at the modem and the router and i couldnt find anything about vpn. I guess ill have to stick with 1362 awhile.

    If you think its the router, i have an Linksys Network Everywhere Firmware version 1.0 Release 08 router.

    I need an optimal connection for 1500/256 in a 1362 MTU.
    PLZ HELP

Similar Threads

  1. Need help setting the mtu..it wont change.
    By liono in forum Broadband Tweaks Help
    Replies: 11
    Last Post: 04-08-04, 03:04 PM
  2. Can't change MTU under XP :(
    By Rak92 in forum Broadband Tweaks Help
    Replies: 6
    Last Post: 09-05-01, 01:37 PM
  3. Tweak tester/ I can't change MTU value.
    By bruce381 in forum Broadband Tweaks Help
    Replies: 0
    Last Post: 08-18-01, 12:36 AM
  4. Can't change my MTU
    By JimMorrison3169 in forum Broadband Tweaks Help
    Replies: 3
    Last Post: 06-02-01, 09:07 PM
  5. How to change MTU setting in W2K?
    By gsb in forum Broadband Tweaks Help
    Replies: 1
    Last Post: 04-11-01, 07:29 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •