frame-relay split-horizon

[teru-lei]

Hi All,

I just need to clarify split-horizon for frame-relay. I remember that for frame-relay point-to-multipoint interface, split-horizon will be disabled in physical interface by default, all subinterfaces and point-to-point interface will not be disabled. But I am not sure and I can not find the documents. Can anybody help me?

Thank You!

Best Regards

Teru Lei

[ankurbhasin]

Hi teru,

In frame replay point to multipoint enviroment which is also known as hub to spoke split horizon is enabled and that is the reason subinterface is recommended to avoid the problem for split horizon.

Check this out

http://www.alliancedatacom.com/manufacturers/cisco-systems/framerelay_design/subinterfaces.asp

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1918.htm

http://www.ciscopress.com/articles/article.asp?p=170741&seqNum=5&rl=1

HTH

Ankur

[teru-lei]

Thanks for your reply. I mean that I remember in certain condition by default cisco will disable split-horizon in frame-relay environment. I remember it's frame-relay multipoint physical interface. But not sure.

[mounirmohamed]

Dear Teru Lei,

Whene single physical interface si used routing problem arise, because due to Split-Horizon rule the update received on the interface cannot send back through the same interface

Best Regards,

Mounir Mohamed