Hi Giuseppe ,

Thanks for pointing out.

I have to keep in mind that few things are specific to IOS what i said is true for IOS XR but not for IOS.

"Use the passive-interface command to disable the sending of routing updates on an interface. The particular subnet continues to advertise to other interfaces, and updates from other routers on that interface continue to be received and processed."

http://www.cisco.com/en/US/docs/ios_xr_sw/iosxr_r3.7/routing/command/reference/rr37egp.html#wp1024986