RE: TCPPTP connection profiles - how to change

Further to Scotts input, I agree with the theory, but unfortunately the
iSeries (at least 5.1) does not seem to work that way.
Here is the scenario:

We have a PPP originators profile for dial-out to the remote system (we are
the client).
IP addresses (including DNS) are defined as dynamic

When the PPP connection is established, routes are automatically added to
the routing entries for the local and remote ends.
So far so good.
However the TCP negotiation phase also advises the iSeries of the remote DNS
which is on a different subnet.
Now I would have expected this also to be added automatically to the routing
entries, but it is not. Possibly a bug ?
We can get the remote DNS from the negotiation log, and then we tried to add
it with ADDTCPRTE
This is not allowed, with the error message:
Message . . . . :   Associated interface for NEXTHOP parameter value
  10.100.61.254 not found.
Cause . . . . . :   No interface was found that can be used by this route.
In
  order for an interface to be usable, the following must be true:
    -- The interface must be in the same logical network as the specified
next
  hop.  In order for an interface to be in the same network, the logical AND
  of the NEXTHOP parameter with the interface subnet mask must match the
  network ID of the interface.
Now the routing entry 10.100.61.254 DOES exist - this is the remote end,
dynamically allocated, and was added automatically during the TCP
negotiation.
But the DNS entry we were then trying to add is 10.100.62.0 (also tried
10.100.62.50 which is the actual DNS), and as this is a different subnet, so
ADDTCPRTE won't add it.

Unfortunately we don't know the DNS before the dial-up.
(By the way, Windows gets this right). I am still sure that the DNS entry
should be added automatically by TCP and this is a bug or ommission.
Otherwise whats the point in having the parameter in the PPP profile for
dynamically allocating DNS?

As a result the call to the remote host fails using the host name.

If we take a gamble and put a static route for 10.100.62.0 into the PPP
connection profile, this is added automatically on connection and the host
is found.
Hence (hope you are all still with us here :-) ), plan B was to try to get
the DNS entry into the PPP profile programmatically.
And thats the reason for the initial request - we can't find a way to
programmatically alter or add a PPP connection profile that will also add
the static route.

All this occurs because we don't the remote DNS prior to the call.

Hope at least some of this is clear(ish)

Regards

Ian Patterson
Grange Management Consultants
tel 01947 880458
www.grange-systems.co.uk




-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Scott Klement
Sent: 21 April 2004 16:44
To: Midrange Systems Technical Discussion
Subject: Re: TCPPTP connection profiles - how to change



First, let me say that I've never done dial-up TCP/IP from an iSeries.  I
use FreeBSD machines for that, and have been doing so since before
SLIP/PPP existed on the iSeries.

However, having said that, the IP layer usually doesn't know or care what
the physical transport layer is.  It's a basic philosophy of TCP/IP -- it
can be run over any sort of transport (Ethernet, Token-Ring, Modem, Serial
Cable, ISDN, CSU/DSU, etc, etc) and software shouldn't need to know
anything about that physical layer.

Therefore, wouldn't the commands to add/remove routes be ADDTCPRTE,
RMVTCPRTE, CHGTCPRTE, etc?   And the API be ioctl()?

I know that on Unix or Windows systems I can modify the routing table for
a dial-up interface using the standard routing commands.  Although I've
never tried it, I would sure expect OS/400 to work the same way.


On Wed, 21 Apr 2004, Ian Patterson wrote:

> We use originators TCPPTP connection profiles for outgoing connections
with
> PPP dial-up
> These are created with Ops Nav. (OS400 is 5.1)
>
> We would like to programatically change part of the profile via an API or
> similar, but can not find any references to this. Nor can we find any CL
> commands other than simple add or remove. The ADDTCPPTP command does not
> allow input for TCP routing info.
>
> Does anyone know if it is possible to change these profiles - in
particular
> the section dealing with default / static routes.
>
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