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Hi,

I would be grateful if someone could clarify my rather confused ideas of the
10 connection limit on XP/2000 when its being used as a server. (I realise
that XP is really a client op sys with limited server capability, I am also
aware you can kludge the number to 40, but assume I do not want to do that).

As I understand it XP Pro will support 10 simultaneous inbound (SYN)
connections (5 for XP Home). My confusion arises as to what exactly
constitutes an inbound connection. Please correct me if I'm wrong (or tell
if I'm right!). Say I'm using XP Pro as an ICS server or as an iis server

Queries:
I believe that Internet Explorer on a client will open 2 separate
connections to the XP pro server, so is it true that a maximum of 5 IE
sessions can run at once?

If you opened IE 5 times on one machine would that soak up all 10 slots?

Could you run a maximum of 5 machines with 1 IE session each? Or could I run
10 clients each running IE.?

If I was running a program using sockets.... 1 socket connection
client->server would correspond to one connection right? Would 2 sockets on
different ports from the same client machine soak up 2 connections on the
server or one.

I suppose my main confusion here is whether the 'connection' refers to a
clients IP address only (i.e. can connect 10 client MACHINES) or (I
suppose) a IPaddress/Port pair. If the limit is per machine, is there a
limit on the number of sockets that an individual client could open to the
server??

I believe a 10 tcp/ip connections limit has been introduced in SP2 for XP as
a defence against spreading virus/worms. Is this the same thing as the 10
connection limit for the XP server or is this a separate limit applicable to
XP when used normally as a client?

Final points:
I believe iis has a default connection limit of 10 irrespective of op sys
(although the limit can be legitimately changed in the registry) True?
Win Me and 98 have no connection limit when used as servers (e.g. ICS
server) true?

Hoping thats is resonably coherent! Thanks for your time.
regards
Bill

Bill wrote:
> Hi,
>
> I would be grateful if someone could clarify my rather confused ideas
> of the 10 connection limit on XP/2000 when its being used as a
> server. (I realise that XP is really a client op sys with limited
> server capability, I am also aware you can kludge the number to 40,
> but assume I do not want to do that).
>

You will probably get better responses to this on the .inetserver.iis group.
Most of us regulars are programmers who only do a little admin stuff when
needed. The admin-types will more likely be at the iis group.

--
Microsoft MVP -- ASP/ASP.NET
Please reply to the newsgroup. The email account listed in my From
header is my spam trap, so I don't check it very often. You will get a
quicker response by posting to the newsgroup.

> Hi,
>
> I would be grateful if someone could clarify my rather confused ideas of the
> 10 connection limit on XP/2000 when its being used as a server. (I realise
> that XP is really a client op sys with limited server capability, I am also
> aware you can kludge the number to 40, but assume I do not want to do that).
>
> As I understand it XP Pro will support 10 simultaneous inbound (SYN)
> connections (5 for XP Home). My confusion arises as to what exactly
> constitutes an inbound connection. Please correct me if I'm wrong (or tell
> if I'm right!). Say I'm using XP Pro as an ICS server or as an iis server
>

Yes this is true. I'm not aware of the kludge but I suspect the only reason
the limit is present is to maintain a differentiation between client and
server products. If the machine is not a Users PC then I can see no reason
not to increase it's activity in this way.


> Queries:
> I believe that Internet Explorer on a client will open 2 separate
> connections to the XP pro server, so is it true that a maximum of 5 IE
> sessions can run at once?
>
By default IE can open a maximum of 2 connections to the same server. The
key point here is that it does when it is actively fetching things from the
server. Most of the time IE will not have a connection to anything.
Remember HTTP is a connectionless protocol.

> If you opened IE 5 times on one machine would that soak up all 10 slots?
>

If you had 5 actual IExplorer instances running at the same time and all 5
were actively fetching the same XP machine then yes you could fill up the 10
available connections


> Could you run a maximum of 5 machines with 1 IE session each? Or could I run
> 10 clients each running IE.?
>
You could run as many IE instances on as many machines you like but only 5
can 'active' at the same time.

> If I was running a program using sockets.... 1 socket connection
> client->server would correspond to one connection right? Would 2 sockets on
> different ports from the same client machine soak up 2 connections on the
> server or one.
>

Yes a connection is defined as a socket on the client being connected to a
socket on the server.

> I suppose my main confusion here is whether the 'connection' refers to a
> clients IP address only (i.e. can connect 10 client MACHINES) or (I
> suppose) a IPaddress/Port pair. If the limit is per machine, is there a
> limit on the number of sockets that an individual client could open to the
> server??
>

More than one connection can be made even on the same IP/Port. It's not per
machine. The limit of how many individual connections a client can make is
controlled by how many outbound ports its allowed to create (which is a lot
more than 10).


> I believe a 10 tcp/ip connections limit has been introduced in SP2 for XP as
> a defence against spreading virus/worms. Is this the same thing as the 10
> connection limit for the XP server or is this a separate limit applicable to
> XP when used normally as a client?
>

I'm not aware of any limit being imposed on server products.

> Final points:
> I believe iis has a default connection limit of 10 irrespective of op sys
> (although the limit can be legitimately changed in the registry) True?
> Win Me and 98 have no connection limit when used as servers (e.g. ICS
> server) true?

Sorry don't know the answer to this one. Would you really want to use Win98
as a server??

>
> Hoping thats is resonably coherent! Thanks for your time.
> regards
> Bill
>
>
>

Thanks for your replies.
As Bob suggested I cross posted. If anyone would like to comment further
maybe it woud be better to use the iis forum version of this post.
Thanks
Bill
p.s The query about ME/98 was just curiousity. I would only use 98 for a
server if I deserved some serious punishment!!


"Bill" wrote:

> Hi,
>
> I would be grateful if someone could clarify my rather confused ideas of the
> 10 connection limit on XP/2000 when its being used as a server. (I realise
> that XP is really a client op sys with limited server capability, I am also
> aware you can kludge the number to 40, but assume I do not want to do that).
>
> As I understand it XP Pro will support 10 simultaneous inbound (SYN)
> connections (5 for XP Home). My confusion arises as to what exactly
> constitutes an inbound connection. Please correct me if I'm wrong (or tell
> if I'm right!). Say I'm using XP Pro as an ICS server or as an iis server
>
> Queries:
> I believe that Internet Explorer on a client will open 2 separate
> connections to the XP pro server, so is it true that a maximum of 5 IE
> sessions can run at once?
>
> If you opened IE 5 times on one machine would that soak up all 10 slots?
>
> Could you run a maximum of 5 machines with 1 IE session each? Or could I run
> 10 clients each running IE.?
>
> If I was running a program using sockets.... 1 socket connection
> client->server would correspond to one connection right? Would 2 sockets on
> different ports from the same client machine soak up 2 connections on the
> server or one.
>
> I suppose my main confusion here is whether the 'connection' refers to a
> clients IP address only (i.e. can connect 10 client MACHINES) or (I
> suppose) a IPaddress/Port pair. If the limit is per machine, is there a
> limit on the number of sockets that an individual client could open to the
> server??
>
> I believe a 10 tcp/ip connections limit has been introduced in SP2 for XP as
> a defence against spreading virus/worms. Is this the same thing as the 10
> connection limit for the XP server or is this a separate limit applicable to
> XP when used normally as a client?
>
> Final points:
> I believe iis has a default connection limit of 10 irrespective of op sys
> (although the limit can be legitimately changed in the registry) True?
> Win Me and 98 have no connection limit when used as servers (e.g. ICS
> server) true?
>
> Hoping thats is resonably coherent! Thanks for your time.
> regards
> Bill
>
>
>

HI Bill,

I have replied the issue in microsoft.public.inetserver.iis group. Please
go to there and find out whether the issue is clear. Thanks!

Yuan Ren [MSFT]
Microsoft Online Support