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SAP R/3 login problem through tunnel

Hi friends,

Just a peculiar problem with logging into SAP R/3 through a tunnel

Remote Clients are unable to login to SAP R/3 Ver 4.7 server at central office. However, they are able to ping to the SAP server!!

The following are the details:

Remote End router : Cisco 2610 IOS : 12.0(5)XK1

Central office router : Cisco 1721 IOS : 12.3(5e)

A tunnel has been configured on both ends with IP address range of

10.1.1.0 / 30. I am able to ping from one tunnel to the other.

However, with another alternative link (Leased Line) without tunnel confuguration, the remote clients are able to access the SAP server.

I changed the MTU settings for the tunnel interfaces to 1500, but it did not work.

I would also like to add that there is one more remote location router with IOS 12.4(3b) that is having successful SAP server connectivity with central office router in a tunnel configuration.

So, I strongly suspect the IOS version being a cause here. But I am not really in a position to upgrade the IOS from 12.0 to a higher version as I only have 8MB of flash memory.

Are there any options that I can try in this scenario? Thanks a lot for your help in advance.

Thanks a lot Gautam

Reply to
gautamzone
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Hi Gautam,

We encounter the same issue, some version of SAP put the do not fragment bit to set. Meaning that if for some reason, the packets needs to be fragmented (depending on the path you go through), your packet will be simply dropped.

Solution we applied was to set the MTU on the server to 1300 (maybe yuou can fine tune this), by editing the registry.

Reply to
Haitingus

Try pings with larger packet sizes to see if this is a MTU issue. Like the last poster suggested, this could have something to do with the don't-fragment (DF) bit having to be cleared. Check out the following link that explains interaction between MTU and DF bit being set when GRE is involved

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Cisco da Gama
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Reply to
ciscodagama

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