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SAP crashes with two "gateway" entries in TCP/IP on Windows

First off:
 1) I have no knowledge of SAP, how it connects, etc.
 2) I do not have access to SAP server whatsoever.
 3) I'm pretty handy with networking in general.
 4) I do not have good communications with the SAP and router administrators.
 5) I have access to the DHCP server so I can easily pass various informations.

 6) I am on network 10.20.41.x, subnet mask of 255.255.255.0.
 7) Our internet router is 10.20.41.29 that connects straight to DSL internet.
 8) The router that passes info to SAP (somehow) is 10.20.41.254.
 9) The SAP application servers are 10.10.200.120 and 10.20.200.100.

If I have "Default Gateways" entries in Windows 2000/XP for 10.20.41.29 and 10.20.41.254 SAP generally works okay for long periods of time, but will crash out with this error:

partner not reached (host 10.10.200.100, service sapdp00)
WSAECONNREFUSED: Connection refused
Do you want to see the detailed error description?

Often the computer will need to be rebooted to reconnect, sometimes just clicking reconnect will work.

If I put in just the one router 10.20.41.254 into TCP/IP settings without the internet router, everything is PERFECT and it never crashes.

Going with a proxy server would probably eliminate this issue, however I'd like to work with the hardware at hand.

Any help on solving this problem will be greatly appreciated.
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UrbanRiot
Asked:
UrbanRiot
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1 Solution
 
adamdrayerCommented:
you should really only have one gateway.  If using the 10.20.41.254 gateway works, then what's the problem?
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UrbanRiotAuthor Commented:
How would the computers know how to access the internet?
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adamdrayerCommented:
to understand the full routing table, you really have to know the full network architecture, but assuming the 10.20.41.254 router is the only router then:

All packets not destined for 10.20.41.x will be sent to the gateway 10.20.41.254.  Then that router will examine what the destination IP address is and send packets destined for the 10.20.200.x network to the proper interface, and all other packets it will send to 10.20.41.29

That is assuming there are no other routers or subnets on your network.

Basically, all requests to IP addresses not on a local subnet should be directed to a router or similar device(gateway)  Then that gateway is configured with routing tables to send the packet to the next "hop".

example:
you want to access www.google.com, that's IP address is 64.233.161.104.  Your computer recognizes that this is not on it's network, so it passes it to its gateway. In this case it should be the 10.20.41.254 router.  The router looks at it, and doesn't have a specific place to send it, so it sends it to IT's gateway.  This should be 10.20.41.29.  If the request for destined for 10.20.200.x, then the router would send it elsewhere.  To the proper place.

Basically local subnets should be routed explicitly, and all internet traffic will be traffic not explicitly routed so it will be directed to gateways.  So if the comptuers have 10.20.41.254 as a gateway, and that router has 10.20.41.29 as a gateway, then internet traffic will be routed to the outside properly.
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