R:[ns] Route to base_stn not known: dropping pkt

[Bordes Marta <Marta.Bordes@CSELT.IT>]

Hello,

The message "warning:Route to base_stn not known: dropping pkt" is generated
by the mobile node's DSDV agent (see ns/dsdv/dsdv.cc). DSDV agent always
tries to send packets to the base station referred in the variable base_stn_
of the class MobileNode (see ns/mobilenode.cc). In wireless3.tcl, with the
instruction

set HAaddress [AddrParams set-hieraddr [$HA node-addr]]
[$MH set regagent_] set home_agent_ $HAaddress

we set base_stn_ with the address of the home agent.

When the mobile node performs a handoff, after receiving a new agent
advertisement (from the foreign agent), it modifies the value of base_stn_
with the address of the foreign agent (see mip-reg.cc).

The warning message is caused because the mobile node is trying to send a
packet (probably an acknowledgement to a received TCP packet) to the old
base station, but it is not under its coverage area and it has not updated
the value of base_stn_ yet. 

I hope it helps,



Marta Bordes.

marta.bordes@cselt.it
> ----------
> Da:	scao@lerc.nasa.gov[SMTP:scao@lerc.nasa.gov]
> Inviato:	mercoled� 31 maggio 2000 0.00
> A:	ns-users@mash.CS.Berkeley.EDU
> Cc: 	klan@usc.edu
> Oggetto:	[ns] Route to base_stn not known: dropping pkt
> 
> Hi ns users,
> 
> For wireless3.tcl in Marc Greis's tutorial, I changed 5Mb to 100Mb, and
> 2ms 
> to 5ms; When I run it, the following message appears: "warning:Route to 
> base_stn not known: dropping pkt".   Could you tell me what's wrong?   If
> I 
> change back 100Mb to 5Mb, and 5ms to 2ms, no error messages.
> 
> Thanks.
> 
> Sun Cao
> 
>