SNA Server on Ethernet cannot talk to AS/400 on token ring

[ddisalvo]

We have an SNA server on Ethernet and it cannot talk to a token ring device Q159462 from microsoft suggests to disable LLC local Acknowledgement.

Does anyone have any suggestions and how can I disable LLC?

[dixho]

You can do DLSw FST. I do not find an example of FST. The configuration guide for FST is as follows:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fibm_c/bcfpart2/bcfdlsw.htm#1002472

Basically, it has a very similar configuration as TCP encaupsulation. Just replace "TCP" by "FST" in the dlsw remote-peer statements.

Please note that FST does not offer segmentation/fragmentation. If the LLC2/DLC frames are larger than 1400+ bytes, the router just drops the packets. Make sure that the token ring stations do not send packets larger 1400+ bytes.

For your information, RIF passthrough is another useful option. Please note that RIF pass through DOES NOT support token ring to ethernet, as documented in the following URL:

http://www.cisco.com/warp/public/cc/pd/ibsw/ibdlsw/tech/dls24_rg.htm

One final comment. I have been supporting DLSw and Cisco routers for 4 years. I have worked with a lot of customers setting up MS SNA server and Cisco routers. I have never worked on a case which Cisco routers fail to forward SAMBE. I am working with the development group and find out if this is an IOS bug or not.

[dixho]

I checked with the development team as well as TAC team all over the world. No one has heard about this problem. We (TAC and development team) do not think that this is an issue. If I were you, I will not do FST encapsulation (i.e. disable LLC2 local ack). We will contact Microsoft and find out details.

[ddisalvo]

Thanks for the efforts.