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

• To: ns-users@mash.CS.Berkeley.EDU, "'scao@lerc.nasa.gov'" <scao@lerc.nasa.gov>
• Subject: R:[ns] Route to base_stn not known: dropping pkt
• From: Bordes Marta <Marta.Bordes@CSELT.IT>
• Date: Thu, 01 Jun 2000 18:33:46 +0200
• Sender: owner-ns-users@mash.CS.Berkeley.EDU

---

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,