MTU size for Windows 2003

We are trying to get more speed out of our Windows 2003, currently they are
only topping out at 230 MB per second on a CISCO 6513 switch. Should we
use a larger size that 1514 for the MTU?

Any thoughts would help us.

Thanks,
Eric Sabo

Hello,

Is it Mega bits or Mega Bytes ? B in caps is normally for Bytes.

Changing MTU will overload the switch as others machines are still in 1500.

Do you have the latest driver ?
Do you have Service pack 2 or the network scalable pack ?
Do you have a teaming on your network card ? is it active/active ?
What is the service behinds ? disk system may be the guilty one.


--
Cordialement,
Mathieu CHATEAU
English blog: http://lordoftheping.blogspot.com
French blog: http://www.lotp.fr


"Sabo, Eric" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> We are trying to get more speed out of our Windows 2003, currently they
> are only topping out at 230 MB per second on a CISCO 6513 switch.
> Should we use a larger size that 1514 for the MTU?
>
> Any thoughts would help us.
>
> Thanks,
> Eric Sabo
>

"Sabo, Eric" <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> We are trying to get more speed out of our Windows 2003, currently
> they are only topping out at 230 MB per second on a CISCO 6513 switch.
> Should we use a larger size that 1514 for the MTU?
>
> Any thoughts would help us.
>
> Thanks,
> Eric Sabo
>
>

Definitely not -- some protocols and services will fail if you do this, and
as the other poster mentioned you can overload switches, plus routers might
drop packets.

Are you sure the server is what's slow? The switch might be misconfigured
somehow, especially if there has been experimentation with switch
settings.. Test the server with other computers on the same switch
port/LAN.

Also test other server funtionality if possible, it might be a software
problem, not a prob with the OS.

FA

MegaBytes

Yes - the latest drivers are being used
Service Pack 2 is installed
No teaming is being used

I did a perform log file and do not see any bottlenecks on the servers.


"Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
news:eD1%(E-Mail Removed)...
> Hello,
>
> Is it Mega bits or Mega Bytes ? B in caps is normally for Bytes.
>
> Changing MTU will overload the switch as others machines are still in
> 1500.
>
> Do you have the latest driver ?
> Do you have Service pack 2 or the network scalable pack ?
> Do you have a teaming on your network card ? is it active/active ?
> What is the service behinds ? disk system may be the guilty one.
>
>
> --
> Cordialement,
> Mathieu CHATEAU
> English blog: http://lordoftheping.blogspot.com
> French blog: http://www.lotp.fr
>
>
> "Sabo, Eric" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> We are trying to get more speed out of our Windows 2003, currently they
>> are only topping out at 230 MB per second on a CISCO 6513 switch. Should
>> we use a larger size that 1514 for the MTU?
>>
>> Any thoughts would help us.
>>
>> Thanks,
>> Eric Sabo
>>
>

The ports are set to 1000 and full.

Vlan are set correctly.

"FenderAxe" <(E-Mail Removed)> wrote in message
news:Xns99BE2F7D227faaxecom@198.186.190.163...
> "Sabo, Eric" <(E-Mail Removed)> wrote in
> news:(E-Mail Removed):
>
>> We are trying to get more speed out of our Windows 2003, currently
>> they are only topping out at 230 MB per second on a CISCO 6513 switch.
>> Should we use a larger size that 1514 for the MTU?
>>
>> Any thoughts would help us.
>>
>> Thanks,
>> Eric Sabo
>>
>>
>
> Definitely not -- some protocols and services will fail if you do this,
> and
> as the other poster mentioned you can overload switches, plus routers
> might
> drop packets.
>
> Are you sure the server is what's slow? The switch might be misconfigured
> somehow, especially if there has been experimentation with switch
> settings.. Test the server with other computers on the same switch
> port/LAN.
>
> Also test other server funtionality if possible, it might be a software
> problem, not a prob with the OS.
>
> FA

That may not be the recommended way for 1000. For example, i read an HP
paper saying to let it to auto-1000 and i think you can't even set duplex on
1000 ports on last HP firmware.



--
Cordialement,
Mathieu CHATEAU
English blog: http://lordoftheping.blogspot.com
French blog: http://www.lotp.fr


"Sabo, Eric" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> The ports are set to 1000 and full.
>
> Vlan are set correctly.
>
> "FenderAxe" <(E-Mail Removed)> wrote in message
> news:Xns99BE2F7D227faaxecom@198.186.190.163...
>> "Sabo, Eric" <(E-Mail Removed)> wrote in
>> news:(E-Mail Removed):
>>
>>> We are trying to get more speed out of our Windows 2003, currently
>>> they are only topping out at 230 MB per second on a CISCO 6513 switch.
>>> Should we use a larger size that 1514 for the MTU?
>>>
>>> Any thoughts would help us.
>>>
>>> Thanks,
>>> Eric Sabo
>>>
>>>
>>
>> Definitely not -- some protocols and services will fail if you do this,
>> and
>> as the other poster mentioned you can overload switches, plus routers
>> might
>> drop packets.
>>
>> Are you sure the server is what's slow? The switch might be misconfigured
>> somehow, especially if there has been experimentation with switch
>> settings.. Test the server with other computers on the same switch
>> port/LAN.
>>
>> Also test other server funtionality if possible, it might be a software
>> problem, not a prob with the OS.
>>
>> FA
>
>

Hello,

you use teaming to double the capacity.
Are you sure client can handle more speed ?
It may the client that slow server's speed.

Did you change tcp windows on the server ?
What sort of traffic is it ? http ?

--
Cordialement,
Mathieu CHATEAU
English blog: http://lordoftheping.blogspot.com
French blog: http://www.lotp.fr


"Sabo, Eric" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> MegaBytes
>
> Yes - the latest drivers are being used
> Service Pack 2 is installed
> No teaming is being used
>
> I did a perform log file and do not see any bottlenecks on the servers.
>
>
> "Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
> news:eD1%(E-Mail Removed)...
>> Hello,
>>
>> Is it Mega bits or Mega Bytes ? B in caps is normally for Bytes.
>>
>> Changing MTU will overload the switch as others machines are still in
>> 1500.
>>
>> Do you have the latest driver ?
>> Do you have Service pack 2 or the network scalable pack ?
>> Do you have a teaming on your network card ? is it active/active ?
>> What is the service behinds ? disk system may be the guilty one.
>>
>>
>> --
>> Cordialement,
>> Mathieu CHATEAU
>> English blog: http://lordoftheping.blogspot.com
>> French blog: http://www.lotp.fr
>>
>>
>> "Sabo, Eric" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> We are trying to get more speed out of our Windows 2003, currently they
>>> are only topping out at 230 MB per second on a CISCO 6513 switch. Should
>>> we use a larger size that 1514 for the MTU?
>>>
>>> Any thoughts would help us.
>>>
>>> Thanks,
>>> Eric Sabo
>>>
>>
>
>

I know when you go into their network configuration utility it does not
allow 1500 bytes.

You can hard code most speeds with HP NICs.

My question would be is how would one tell if 1514 bytes is not working or
chopping the packets, is there anything on the server I can see.


"Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> That may not be the recommended way for 1000. For example, i read an HP
> paper saying to let it to auto-1000 and i think you can't even set duplex
> on 1000 ports on last HP firmware.
>
>
>
> --
> Cordialement,
> Mathieu CHATEAU
> English blog: http://lordoftheping.blogspot.com
> French blog: http://www.lotp.fr
>
>
> "Sabo, Eric" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> The ports are set to 1000 and full.
>>
>> Vlan are set correctly.
>>
>> "FenderAxe" <(E-Mail Removed)> wrote in message
>> news:Xns99BE2F7D227faaxecom@198.186.190.163...
>>> "Sabo, Eric" <(E-Mail Removed)> wrote in
>>> news:(E-Mail Removed):
>>>
>>>> We are trying to get more speed out of our Windows 2003, currently
>>>> they are only topping out at 230 MB per second on a CISCO 6513 switch.
>>>> Should we use a larger size that 1514 for the MTU?
>>>>
>>>> Any thoughts would help us.
>>>>
>>>> Thanks,
>>>> Eric Sabo
>>>>
>>>>
>>>
>>> Definitely not -- some protocols and services will fail if you do this,
>>> and
>>> as the other poster mentioned you can overload switches, plus routers
>>> might
>>> drop packets.
>>>
>>> Are you sure the server is what's slow? The switch might be
>>> misconfigured
>>> somehow, especially if there has been experimentation with switch
>>> settings.. Test the server with other computers on the same switch
>>> port/LAN.
>>>
>>> Also test other server funtionality if possible, it might be a software
>>> problem, not a prob with the OS.
>>>
>>> FA
>>
>>
>

You seem to not have read one of my previous post:

you can use teaming to double the bandwith.
Are you sure your client can handle more speed ?
It may the client that slow server's speed.

Did you change tcp windows on the server ?
What sort of traffic is it ? http ?


--
Cordialement,
Mathieu CHATEAU
English blog: http://lordoftheping.blogspot.com
French blog: http://www.lotp.fr


"Sabo, Eric" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
>I know when you go into their network configuration utility it does not
>allow 1500 bytes.
>
> You can hard code most speeds with HP NICs.
>
> My question would be is how would one tell if 1514 bytes is not working or
> chopping the packets, is there anything on the server I can see.
>
>
> "Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> That may not be the recommended way for 1000. For example, i read an HP
>> paper saying to let it to auto-1000 and i think you can't even set duplex
>> on 1000 ports on last HP firmware.
>>
>>
>>
>> --
>> Cordialement,
>> Mathieu CHATEAU
>> English blog: http://lordoftheping.blogspot.com
>> French blog: http://www.lotp.fr
>>
>>
>> "Sabo, Eric" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> The ports are set to 1000 and full.
>>>
>>> Vlan are set correctly.
>>>
>>> "FenderAxe" <(E-Mail Removed)> wrote in message
>>> news:Xns99BE2F7D227faaxecom@198.186.190.163...
>>>> "Sabo, Eric" <(E-Mail Removed)> wrote in
>>>> news:(E-Mail Removed):
>>>>
>>>>> We are trying to get more speed out of our Windows 2003, currently
>>>>> they are only topping out at 230 MB per second on a CISCO 6513 switch.
>>>>> Should we use a larger size that 1514 for the MTU?
>>>>>
>>>>> Any thoughts would help us.
>>>>>
>>>>> Thanks,
>>>>> Eric Sabo
>>>>>
>>>>>
>>>>
>>>> Definitely not -- some protocols and services will fail if you do this,
>>>> and
>>>> as the other poster mentioned you can overload switches, plus routers
>>>> might
>>>> drop packets.
>>>>
>>>> Are you sure the server is what's slow? The switch might be
>>>> misconfigured
>>>> somehow, especially if there has been experimentation with switch
>>>> settings.. Test the server with other computers on the same switch
>>>> port/LAN.
>>>>
>>>> Also test other server funtionality if possible, it might be a software
>>>> problem, not a prob with the OS.
>>>>
>>>> FA
>>>
>>>
>>
>
>

I am not using teaming on any server hardware.

No changes were made with the TCP on the server.

file copies and backups.

I tried connecting four clients to on server and it does not go above 100 MB
which is 10% throughput of a gigabit adapter

"Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> You seem to not have read one of my previous post:
>
> you can use teaming to double the bandwith.
> Are you sure your client can handle more speed ?
> It may the client that slow server's speed.
>
> Did you change tcp windows on the server ?
> What sort of traffic is it ? http ?
>
>
> --
> Cordialement,
> Mathieu CHATEAU
> English blog: http://lordoftheping.blogspot.com
> French blog: http://www.lotp.fr
>
>
> "Sabo, Eric" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>>I know when you go into their network configuration utility it does not
>>allow 1500 bytes.
>>
>> You can hard code most speeds with HP NICs.
>>
>> My question would be is how would one tell if 1514 bytes is not working
>> or chopping the packets, is there anything on the server I can see.
>>
>>
>> "Mathieu CHATEAU" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>>> That may not be the recommended way for 1000. For example, i read an HP
>>> paper saying to let it to auto-1000 and i think you can't even set
>>> duplex on 1000 ports on last HP firmware.
>>>
>>>
>>>
>>> --
>>> Cordialement,
>>> Mathieu CHATEAU
>>> English blog: http://lordoftheping.blogspot.com
>>> French blog: http://www.lotp.fr
>>>
>>>
>>> "Sabo, Eric" <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)...
>>>> The ports are set to 1000 and full.
>>>>
>>>> Vlan are set correctly.
>>>>
>>>> "FenderAxe" <(E-Mail Removed)> wrote in message
>>>> news:Xns99BE2F7D227faaxecom@198.186.190.163...
>>>>> "Sabo, Eric" <(E-Mail Removed)> wrote in
>>>>> news:(E-Mail Removed):
>>>>>
>>>>>> We are trying to get more speed out of our Windows 2003, currently
>>>>>> they are only topping out at 230 MB per second on a CISCO 6513
>>>>>> switch.
>>>>>> Should we use a larger size that 1514 for the MTU?
>>>>>>
>>>>>> Any thoughts would help us.
>>>>>>
>>>>>> Thanks,
>>>>>> Eric Sabo
>>>>>>
>>>>>>
>>>>>
>>>>> Definitely not -- some protocols and services will fail if you do
>>>>> this, and
>>>>> as the other poster mentioned you can overload switches, plus routers
>>>>> might
>>>>> drop packets.
>>>>>
>>>>> Are you sure the server is what's slow? The switch might be
>>>>> misconfigured
>>>>> somehow, especially if there has been experimentation with switch
>>>>> settings.. Test the server with other computers on the same switch
>>>>> port/LAN.
>>>>>
>>>>> Also test other server funtionality if possible, it might be a
>>>>> software
>>>>> problem, not a prob with the OS.
>>>>>
>>>>> FA
>>>>
>>>>
>>>
>>
>>
>