question about network design

[JM]

Here's the scenario:

Small company, 3 locations.
Approx 15 computers (Win XP) each location
Win 2k3 server in main location
The server is DC and runs SQL server and their primary business application
The three locations are networked via VPN (over cable modem internet
service) using SonicWall SOHO2 appliances
Each location is on a different subnet
DHCP in each location is handled by the Sonicwall
The workstations run a full client of their business software, with the
database on the server in the main location

For the most part, things work okay, but one of the locations is having many
problems with its primary business application. After some period of
inactivity by the client computer(s), the app will "time out," generating a
runtime error and necessitating closing out of the app and logging back in
[to the app].

I know I haven't provided enough info to troubleshoot the matter fully, but
my question concerns the issue of the 3 subnets and how DHCP is being
handled. Would it make more sense to use the DC as the DHCP server and put
all the computers on the network on the same subnet?

thank you,

jm

 

[Ace Fekay [MVP]]

In

Here's the scenario:

Small company, 3 locations.
Approx 15 computers (Win XP) each location
Win 2k3 server in main location
The server is DC and runs SQL server and their primary business
application The three locations are networked via VPN (over cable
modem internet service) using SonicWall SOHO2 appliances
Each location is on a different subnet
DHCP in each location is handled by the Sonicwall
The workstations run a full client of their business software, with
the database on the server in the main location

For the most part, things work okay, but one of the locations is
having many problems with its primary business application. After
some period of inactivity by the client computer(s), the app will
"time out," generating a runtime error and necessitating closing out
of the app and logging back in [to the app].

I know I haven't provided enough info to troubleshoot the matter
fully, but my question concerns the issue of the 3 subnets and how
DHCP is being handled. Would it make more sense to use the DC as the
DHCP server and put all the computers on the network on the same
subnet?
thank you,

jm

If you put all locations on the same subnet, then you will be running a
bridged configuration among your sites, and not a routed one. I don't think
you want that. You can use a single DHCP server and create three different
scopes and their own options. To allow DHCP to service the other subnets,
the SOHOs should be able to have the capability to be a DHCP relay, or IP
helper (the terminology depends on the router and not sure what SonicWall
calls it) forwarding to the DC, meaning when it hears a DHCP request, it
forwards it to the DC, and the DC replies back to the SOHO, and the SOHO
will forward on the data.

As far as the time outs on the app, is the app configured differently at
that location than the others? Some type of differerent setting in the
router where it falls 'asleep' during inactivity? Maybe the cable company is
experiencing problems at that location? Sometimes they won't fess up to that
unless you repeatedly call for weeks on end and finally get a manager to put
their better people on it to investigate deeper.

I had that problem with Comcast. Frankly, if you don't push their buttons by
constantly calling them saying the problem still exists and they still won't
fix it or look deeper into it, you'll have to eventually threaten them by
mentioning you may talk to those people that use those three magic letters
that describe their organization, "FCC", they'll give you an "I don't care"
attitude. But before you start pushing them, you really must determine that
it is actually them and not a problem elsewhere, or else it will backfire.


--
Ace
Innovative IT Concepts, Inc (IITCI)
Willow Grove, PA

This posting is provided "AS-IS" with no warranties or guarantees and
confers no rights.

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft MVP - Directory Services
Microsoft Certified Trainer

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[JM]

In

Here's the scenario:

Small company, 3 locations.
Approx 15 computers (Win XP) each location
Win 2k3 server in main location
The server is DC and runs SQL server and their primary business
application The three locations are networked via VPN (over cable
modem internet service) using SonicWall SOHO2 appliances
Each location is on a different subnet
DHCP in each location is handled by the Sonicwall
The workstations run a full client of their business software, with
the database on the server in the main location

For the most part, things work okay, but one of the locations is
having many problems with its primary business application. After
some period of inactivity by the client computer(s), the app will
"time out," generating a runtime error and necessitating closing out
of the app and logging back in [to the app].

I know I haven't provided enough info to troubleshoot the matter
fully, but my question concerns the issue of the 3 subnets and how
DHCP is being handled. Would it make more sense to use the DC as the
DHCP server and put all the computers on the network on the same
subnet?
thank you,

jm

If you put all locations on the same subnet, then you will be running a
bridged configuration among your sites, and not a routed one. I don't
think you want that. You can use a single DHCP server and create three
different scopes and their own options. To allow DHCP to service the other
subnets, the SOHOs should be able to have the capability to be a DHCP
relay, or IP helper (the terminology depends on the router and not sure
what SonicWall calls it) forwarding to the DC, meaning when it hears a
DHCP request, it forwards it to the DC, and the DC replies back to the
SOHO, and the SOHO will forward on the data.

As far as the time outs on the app, is the app configured differently at
that location than the others? Some type of differerent setting in the
router where it falls 'asleep' during inactivity? Maybe the cable company
is experiencing problems at that location? Sometimes they won't fess up to
that unless you repeatedly call for weeks on end and finally get a manager
to put their better people on it to investigate deeper.

I had that problem with Comcast. Frankly, if you don't push their buttons
by constantly calling them saying the problem still exists and they still
won't fix it or look deeper into it, you'll have to eventually threaten
them by mentioning you may talk to those people that use those three magic
letters that describe their organization, "FCC", they'll give you an "I
don't care" attitude. But before you start pushing them, you really must
determine that it is actually them and not a problem elsewhere, or else it
will backfire.

Thank you for the excellent reply.

Point taken on the DHCP and subnets. I think it's okay to leave it like it
is. There is no inherent problem to that.

The other problem, however, is more critical. To answer your question
regarding the possibility that something is different at the problematic
location, the answer is, "apparently not." I've been through the routers
comprehensively, and I cannot find a difference. I even swapped the routers
in the two remote locations, rebuilding the VPN, in an effort to check the
possibility of both hardware and configuration problems. The runtime errors
in the problematic location remain.

And concerning your experience: Guess who our cable provider is? Yep,
Comcast (formerly Time Warner Cable where I am). The only sticking point to
that theory, however, is that the raw internet service in the problematic
location is excellent. Download speeds from internet sites are excellent,
rivaling or even surpassing the raw speeds in the other locations. But when
we pull up one of the two primary business applications, the performance is
noticeably slower than in the other remote location. Screens change more
slowly, things start and shut down more slowly, etc.

This thing has me befuddled.

jm

 

[Kurt]

In

Here's the scenario:

Small company, 3 locations.
Approx 15 computers (Win XP) each location
Win 2k3 server in main location
The server is DC and runs SQL server and their primary business
application The three locations are networked via VPN (over cable
modem internet service) using SonicWall SOHO2 appliances
Each location is on a different subnet
DHCP in each location is handled by the Sonicwall
The workstations run a full client of their business software, with
the database on the server in the main location

For the most part, things work okay, but one of the locations is
having many problems with its primary business application. After
some period of inactivity by the client computer(s), the app will
"time out," generating a runtime error and necessitating closing out
of the app and logging back in [to the app].

I know I haven't provided enough info to troubleshoot the matter
fully, but my question concerns the issue of the 3 subnets and how
DHCP is being handled. Would it make more sense to use the DC as the
DHCP server and put all the computers on the network on the same
subnet?
thank you,

jm

If you put all locations on the same subnet, then you will be running a
bridged configuration among your sites, and not a routed one. I don't
think you want that. You can use a single DHCP server and create three
different scopes and their own options. To allow DHCP to service the other
subnets, the SOHOs should be able to have the capability to be a DHCP
relay, or IP helper (the terminology depends on the router and not sure
what SonicWall calls it) forwarding to the DC, meaning when it hears a
DHCP request, it forwards it to the DC, and the DC replies back to the
SOHO, and the SOHO will forward on the data.

As far as the time outs on the app, is the app configured differently at
that location than the others? Some type of differerent setting in the
router where it falls 'asleep' during inactivity? Maybe the cable company
is experiencing problems at that location? Sometimes they won't fess up to
that unless you repeatedly call for weeks on end and finally get a manager
to put their better people on it to investigate deeper.

I had that problem with Comcast. Frankly, if you don't push their buttons
by constantly calling them saying the problem still exists and they still
won't fix it or look deeper into it, you'll have to eventually threaten
them by mentioning you may talk to those people that use those three magic
letters that describe their organization, "FCC", they'll give you an "I
don't care" attitude. But before you start pushing them, you really must
determine that it is actually them and not a problem elsewhere, or else it
will backfire.

Thank you for the excellent reply.

Point taken on the DHCP and subnets. I think it's okay to leave it like it
is. There is no inherent problem to that.

The other problem, however, is more critical. To answer your question
regarding the possibility that something is different at the problematic
location, the answer is, "apparently not." I've been through the routers
comprehensively, and I cannot find a difference. I even swapped the routers
in the two remote locations, rebuilding the VPN, in an effort to check the
possibility of both hardware and configuration problems. The runtime errors
in the problematic location remain.

And concerning your experience: Guess who our cable provider is? Yep,
Comcast (formerly Time Warner Cable where I am). The only sticking point to
that theory, however, is that the raw internet service in the problematic
location is excellent. Download speeds from internet sites are excellent,
rivaling or even surpassing the raw speeds in the other locations. But when
we pull up one of the two primary business applications, the performance is
noticeably slower than in the other remote location. Screens change more
slowly, things start and shut down more slowly, etc.

This thing has me befuddled.

jm

I'm not sure about Comcast, but cable ISPs typically provide far less
outbound bandwidth than inbound. Go to a decent test site (like
speakeasy.net) and check your bandwidth in both directions.

....kurt

 

[Ace Fekay [MVP]]

In

I'm not sure about Comcast, but cable ISPs typically provide far less
outbound bandwidth than inbound. Go to a decent test site (like
speakeasy.net) and check your bandwidth in both directions.

...kurt

Kurt,

Don't you just love those [sic] Comcast commercials saying how "fast" they
are, when in reality, their upload is only 384 k. I believe their 'business'
line is 768k upload. Sure the download is huge, like 6 megs, which they only
did in some venues only because of the threat of Verizon FIOS.

Unfortunately, cable is purely junk to me...

Cable are the Slowskis to me, especially with their slow uploads. FIOS
coming around, look into it. For the most part, depending on what's
available, I normally don't recommend cable for critical business
applications.

Ace