> OK, So I am still on the hunt for the network delays I am seeing - so
> some questions about network throughput.
>
> My Hardware
>
> Windows Domain Server - (1) 1 GB ethernet
>

Make sure the server NICs are hard-coded for 1 Gbps Full-duplex. 
Gigabitethernet left in auto-detect mode can lead to funky things...

Make sure the switch ports facing the servers also have their speed and 
duplex hardcoded, if possible.

> File Server - (2) 1GB ethernet (bonded to share load into the same switch)
>

How?  Depending on the way it's set up, it can cause major problems with 
the switch.  Disconnect one of the patch cords and see if performance 
improves.  If it does, you had a loop between the two switch ports, and 
the two NICs in your server.  Either reconfigure your NICs to use 
fail-over, or make sure "spanning-tree" is enabled on the switch ports 
facing the server.  Keep in mind that by doing that you will lose your 
2Gbps aggregation speed and the second NIC will only be there to provide 
a host-stanby.

> Patch panel and patch cords are CAT5e
>

Length?  CAT5e specification says that desks-side patch cords must not 
be longer than 3m (10ft), and that switch-side patch cords can not be 
longer than 7m (25ft), while the total length of the premises cabling 
(in the wall) must not exceed 90m (300ft).  See below to know how to do 
this.

> In Wall wiring is combination of CAT5 and CAT5e
>

Do you have lots of internediary patch panel connections (e.g.: desk to 
wiring closet.  Wiring closet to server room main wall.  Server room 
wall to rack patch panel)

> Switch is DELL PowerConnect 2724 running in a non-managed mode
>

According to TFM (which you should R), there are cable-testing functions 
in the switch.  Check to see if you have faulty cabling, exceed the 
length of the standards, or if the premises cabling can really sustain 
1Gbps.  If not, downgrade the user ports to 100 Mbps.

> about 10 users on the network
>

Check, if possible, for rogue user activity (Is anyone running a 
streaming app?  Is anyone acting as a Counterstrike server?  Does anyone 
have NetBEUI turned on by mistake? etc...)

>
> What slowdowns might this kind of setup cause?
>

Apart from the risk of having a spanning-tree loop between the switch 
and the dual-homed server, there's nothing inherently bad about this 
setup. By default it should run fine.

>
> Thanks
>
>
>
>


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>
> How? Depending on the way it's set up, it can cause major problems with
> the switch. Disconnect one of the patch cords and see if performance
> improves. If it does, you had a loop between the two switch ports, and
> the two NICs in your server. Either reconfigure your NICs to use
> fail-over, or make sure "spanning-tree" is enabled on the switch ports
> facing the server. Keep in mind that by doing that you will lose your
> 2Gbps aggregation speed and the second NIC will only be there to provide
> a host-stanby.
>

And by that, I mean "hot-standby".  I Should have proof-read...

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> OK, So I am still on the hunt for the network delays I am seeing - so
> some questions about network throughput.
>
> My Hardware
>
> Windows Domain Server - (1) 1 GB ethernet
>
> File Server - (2) 1GB ethernet (bonded to share load into the same switch)
>
> Patch panel and patch cords are CAT5e
>
> In Wall wiring is combination of CAT5 and CAT5e
>
> Switch is DELL PowerConnect 2724 running in a non-managed mode
>
> about 10 users on the network
>
>
> What slowdowns might this kind of setup cause?
>
>
> Thanks
>
>
>
>

I know someone who had slow network. He discovered that he was 
configured as peer to peer instead of on a domain. This can realy slow 
things down.

Check for crushed or otherwise damaged cables. Any work on a wall 
containint cabling? It could have damaged some cabling.

I think that, at least sometimes, a faulty network adaptor on one 
computer may cause erratic trafic over the network.

Post a reply to this message

On 12/22/2011 10:13 AM, Francois Labreque wrote:

>> OK, So I am still on the hunt for the network delays I am seeing - so
>> some questions about network throughput.
>>
>> My Hardware
>>
>> Windows Domain Server - (1) 1 GB ethernet
>>
>
> Make sure the server NICs are hard-coded for 1 Gbps Full-duplex.
> Gigabitethernet left in auto-detect mode can lead to funky things...
>
> Make sure the switch ports facing the servers also have their speed and
> duplex hardcoded, if possible.
>

I will look into this.

>> File Server - (2) 1GB ethernet (bonded to share load into the same
>> switch)
>>
>
> How? Depending on the way it's set up, it can cause major problems with
> the switch. Disconnect one of the patch cords and see if performance
> improves. If it does, you had a loop between the two switch ports, and
> the two NICs in your server. Either reconfigure your NICs to use
> fail-over, or make sure "spanning-tree" is enabled on the switch ports
> facing the server. Keep in mind that by doing that you will lose your
> 2Gbps aggregation speed and the second NIC will only be there to provide
> a host-stanby.
>

Hmmm - something to look at.  I'll try to run a test in the near future.
It has run like this for 4 years without a visible issue - but that 
could be due to a light load.


>> Patch panel and patch cords are CAT5e
>>
>
> Length? CAT5e specification says that desks-side patch cords must not be
> longer than 3m (10ft), and that switch-side patch cords can not be
> longer than 7m (25ft), while the total length of the premises cabling
> (in the wall) must not exceed 90m (300ft). See below to know how to do
> this.
>

desk-side -   5-10 ft typical - a very few longer - < 15 ft
switch-side - < 3 ft
in wall  -    < 100 ft  (building is 100' long and net room is in the 
middle.

>> In Wall wiring is combination of CAT5 and CAT5e
>>
>
> Do you have lots of internediary patch panel connections (e.g.: desk to
> wiring closet. Wiring closet to server room main wall. Server room wall
> to rack patch panel)
>

server patch directly switch
switch patch to panel
panel run to wall outlet
wall outlet patch to computer


>> Switch is DELL PowerConnect 2724 running in a non-managed mode
>>
>
> According to TFM (which you should R), there are cable-testing functions
> in the switch. Check to see if you have faulty cabling, exceed the
> length of the standards, or if the premises cabling can really sustain
> 1Gbps. If not, downgrade the user ports to 100 Mbps.
>

Working on RTFM - as time allows.
Just set the switch to 'managed mode' while nobody was in the office.
Now to figure out how to 'use' it.



>> about 10 users on the network
>>
>
> Check, if possible, for rogue user activity (Is anyone running a
> streaming app? Is anyone acting as a Counterstrike server? Does anyone
> have NetBEUI turned on by mistake? etc...)
>

We do have people running streaming music and video - and even a small 
minecraft server for local use (guys like to lunch it)

My thought is that the bandwidth that these things use is small enough 
as to not impact usability.  We have never seen things like this impact 
the network before.


Our pipe to the internet is 50/10 and is pretty consistent - but that 
should not overly impact server-client speeds in out office - should it?



>>
>> What slowdowns might this kind of setup cause?
>>
>
> Apart from the risk of having a spanning-tree loop between the switch
> and the dual-homed server, there's nothing inherently bad about this
> setup. By default it should run fine.
>

We have been running the network like this since 2007 without noticing 
any problems.  But with a few extra guys in the office it sounds like it 
could cause some latent problems to crop up.

The spanning-tree loop sounds like something to look into.  I'll run 
some tests with disconnecting a port to see if that may be the cause of 
the problem as well as using the managed features of the switch to run 
down some issues.


Thanks

Post a reply to this message

On 12/23/2011 8:12 AM, Francois Labreque wrote:

>
>>
>> How? Depending on the way it's set up, it can cause major problems with
>> the switch. Disconnect one of the patch cords and see if performance
>> improves. If it does, you had a loop between the two switch ports, and
>> the two NICs in your server. Either reconfigure your NICs to use
>> fail-over, or make sure "spanning-tree" is enabled on the switch ports
>> facing the server. Keep in mind that by doing that you will lose your
>> 2Gbps aggregation speed and the second NIC will only be there to provide
>> a host-stanby.
>>
>
> And by that, I mean "hot-standby". I Should have proof-read...
>

I picked up on that - is there a 'safe' setup that would allow ganging 
of ports like I have?

Post a reply to this message

On 12/23/2011 6:57 PM, Alain wrote:

>> OK, So I am still on the hunt for the network delays I am seeing - so
>> some questions about network throughput.
>>
>> My Hardware
>>
>> Windows Domain Server - (1) 1 GB ethernet
>>
>> File Server - (2) 1GB ethernet (bonded to share load into the same
>> switch)
>>
>> Patch panel and patch cords are CAT5e
>>
>> In Wall wiring is combination of CAT5 and CAT5e
>>
>> Switch is DELL PowerConnect 2724 running in a non-managed mode
>>
>> about 10 users on the network
>>
>>
>> What slowdowns might this kind of setup cause?
>>
>>
>> Thanks
>>
>>
>>
>>
>
> I know someone who had slow network. He discovered that he was
> configured as peer to peer instead of on a domain. This can realy slow
> things down.
>
> Check for crushed or otherwise damaged cables. Any work on a wall
> containint cabling? It could have damaged some cabling.
>
> I think that, at least sometimes, a faulty network adaptor on one
> computer may cause erratic trafic over the network.

I'll set up some monitoring to see if I can see what traffic is flowing.
I am pretty confidant that we are all running on domain.

Cabling to some offices may be suspect - but not too much to do about it 
as it is in-wall.  We may run some patch cords to do some tests.

Thanks

Post a reply to this message

> On 12/23/2011 8:12 AM, Francois Labreque wrote:

>>
>>>
>>> How? Depending on the way it's set up, it can cause major problems with
>>> the switch. Disconnect one of the patch cords and see if performance
>>> improves. If it does, you had a loop between the two switch ports, and
>>> the two NICs in your server. Either reconfigure your NICs to use
>>> fail-over, or make sure "spanning-tree" is enabled on the switch ports
>>> facing the server. Keep in mind that by doing that you will lose your
>>> 2Gbps aggregation speed and the second NIC will only be there to provide
>>> a host-stanby.
>>>
>>
>> And by that, I mean "hot-standby". I Should have proof-read...
>>
>
> I picked up on that - is there a 'safe' setup that would allow ganging
> of ports like I have?
>
>

Look into LACP (IEEE 802.3ad Link Aggregation Control Protocol).  Both 
your NICs and the swith need support it (and be configured for it, 
obviously!)  Cisco also has proprietary equivalents (EtherChannel and 
PAgP) that are sometimes supported by third party hardware.


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> On 12/22/2011 10:13 AM, Francois Labreque wrote:

>>> OK, So I am still on the hunt for the network delays I am seeing - so
>>> some questions about network throughput.
>>>
>>> My Hardware
>>>
>>> Windows Domain Server - (1) 1 GB ethernet
>>>
>>
>> Make sure the server NICs are hard-coded for 1 Gbps Full-duplex.
>> Gigabitethernet left in auto-detect mode can lead to funky things...
>>
>> Make sure the switch ports facing the servers also have their speed and
>> duplex hardcoded, if possible.
>>
>
> I will look into this.
>
>>> File Server - (2) 1GB ethernet (bonded to share load into the same
>>> switch)
>>>
>>
>> How? Depending on the way it's set up, it can cause major problems with
>> the switch. Disconnect one of the patch cords and see if performance
>> improves. If it does, you had a loop between the two switch ports, and
>> the two NICs in your server. Either reconfigure your NICs to use
>> fail-over, or make sure "spanning-tree" is enabled on the switch ports
>> facing the server. Keep in mind that by doing that you will lose your
>> 2Gbps aggregation speed and the second NIC will only be there to provide
>> a host-stanby.
>>
>
> Hmmm - something to look at. I'll try to run a test in the near future.
> It has run like this for 4 years without a visible issue - but that
> could be due to a light load.
>
>
>>> Patch panel and patch cords are CAT5e
>>>
>>
>> Length? CAT5e specification says that desks-side patch cords must not be
>> longer than 3m (10ft), and that switch-side patch cords can not be
>> longer than 7m (25ft), while the total length of the premises cabling
>> (in the wall) must not exceed 90m (300ft). See below to know how to do
>> this.
>>
>
> desk-side - 5-10 ft typical - a very few longer - < 15 ft
> switch-side - < 3 ft
> in wall - < 100 ft (building is 100' long and net room is in the middle.
>

Do not assume anything.  Cabling conduits sometimes take funky routes 
around (or into... but that's a big fire hazard!) ventilation ducts, 
plumbing, elevator shafts, etc...  I've seen cables strung as tight as 
piano wire, I've seen bundles of cables thrown under the floors because 
the cabling guys were too lazy to cut them to the proper lengths, I've 
seen attack ship fire off the shoulder of Orion...

>>> In Wall wiring is combination of CAT5 and CAT5e
>>>
>>
>> Do you have lots of internediary patch panel connections (e.g.: desk to
>> wiring closet. Wiring closet to server room main wall. Server room wall
>> to rack patch panel)
>>
>
> server patch directly switch
> switch patch to panel
> panel run to wall outlet
> wall outlet patch to computer
>
>
>>> Switch is DELL PowerConnect 2724 running in a non-managed mode
>>>
>>
>> According to TFM (which you should R), there are cable-testing functions
>> in the switch. Check to see if you have faulty cabling, exceed the
>> length of the standards, or if the premises cabling can really sustain
>> 1Gbps. If not, downgrade the user ports to 100 Mbps.
>>
>
> Working on RTFM - as time allows.
> Just set the switch to 'managed mode' while nobody was in the office.
> Now to figure out how to 'use' it.
>
>
>
>>> about 10 users on the network
>>>
>>
>> Check, if possible, for rogue user activity (Is anyone running a
>> streaming app? Is anyone acting as a Counterstrike server? Does anyone
>> have NetBEUI turned on by mistake? etc...)
>>
>
> We do have people running streaming music and video - and even a small
> minecraft server for local use (guys like to lunch it)
>
> My thought is that the bandwidth that these things use is small enough
> as to not impact usability. We have never seen things like this impact
> the network before.
>

Things have certainly improved since Doom 1.1 wrecked havoc on company 
LANs in the early 90s, but it's always a good think to know what's out 
there and be ready to limit extra-curricular activies, if it's 
preventing people from working.

>
> Our pipe to the internet is 50/10 and is pretty consistent - but that
> should not overly impact server-client speeds in out office - should it?
>

Unless someone has gotten access to your server and is running a proxy 
from it, no.

>
>
>>>
>>> What slowdowns might this kind of setup cause?
>>>
>>
>> Apart from the risk of having a spanning-tree loop between the switch
>> and the dual-homed server, there's nothing inherently bad about this
>> setup. By default it should run fine.
>>
>
> We have been running the network like this since 2007 without noticing
> any problems. But with a few extra guys in the office it sounds like it
> could cause some latent problems to crop up.
>
> The spanning-tree loop sounds like something to look into. I'll run some
> tests with disconnecting a port to see if that may be the cause of the
> problem as well as using the managed features of the switch to run down
> some issues.
>
>
> Thanks
>


-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
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On 1/3/2012 9:12 AM, Francois Labreque wrote:

>> On 12/23/2011 8:12 AM, Francois Labreque wrote:

>>>
>>>>
>>>> How? Depending on the way it's set up, it can cause major problems with
>>>> the switch. Disconnect one of the patch cords and see if performance
>>>> improves. If it does, you had a loop between the two switch ports, and
>>>> the two NICs in your server. Either reconfigure your NICs to use
>>>> fail-over, or make sure "spanning-tree" is enabled on the switch ports
>>>> facing the server. Keep in mind that by doing that you will lose your
>>>> 2Gbps aggregation speed and the second NIC will only be there to
>>>> provide
>>>> a host-stanby.
>>>>
>>>
>>> And by that, I mean "hot-standby". I Should have proof-read...
>>>
>>
>> I picked up on that - is there a 'safe' setup that would allow ganging
>> of ports like I have?
>>
>>
>
> Look into LACP (IEEE 802.3ad Link Aggregation Control Protocol). Both
> your NICs and the swith need support it (and be configured for it,
> obviously!) Cisco also has proprietary equivalents (EtherChannel and
> PAgP) that are sometimes supported by third party hardware.
>
>

I found a bit of time and put our switch into managed mode and R some of TM.

Looks like it supports "Link Aggregate Groups".

The linux box is set up with aggregation already - ethernet bonding with 
round-robin - actually pretty cool setup that I figured out when I set 
it up.

The switch and linux box are pre 2008 so they don't support the 802.1 - 
but should do the 802.3ad.

Some reading shows that I should be able to link the 2 server ports on 
the switch - don't know if it will make much difference but it seems 
like it is the way it should be.

Will have to try it in the morning when no-one is in the office.

Post a reply to this message

On 1/3/2012 9:21 AM, Francois Labreque wrote:

>
> Do not assume anything. Cabling conduits sometimes take funky routes
> around (or into... but that's a big fire hazard!) ventilation ducts,
> plumbing, elevator shafts, etc... I've seen cables strung as tight as
> piano wire, I've seen bundles of cables thrown under the floors because
> the cabling guys were too lazy to cut them to the proper lengths, I've
> seen attack ship fire off the shoulder of Orion...
>

Our own guys wired the building when they moved in way back - ~1999. 
While likely not the best installation it wasn't the worst either.  It 
is amazing what a bunch of engineers that don't know what htey are doing 
can do?

>>
>> My thought is that the bandwidth that these things use is small enough
>> as to not impact usability. We have never seen things like this impact
>> the network before.
>>
>
> Things have certainly improved since Doom 1.1 wrecked havoc on company
> LANs in the early 90s, but it's always a good think to know what's out
> there and be ready to limit extra-curricular activies, if it's
> preventing people from working.
>

Always on the mind - always keeping an eye out for it.  Conceptually it 
doesn't seem top be the problem, but I am no network expert.

>>
>> Our pipe to the internet is 50/10 and is pretty consistent - but that
>> should not overly impact server-client speeds in out office - should it?
>>
>
> Unless someone has gotten access to your server and is running a proxy
> from it, no.
>

In the office there are no worries, but from out the office - we have 
always tried to have a decent firewall between us and the internet.  But 
that is never a guarantee.  Doesn't seem like something weird is running 
- but I am not a network/computer expert.

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