When you want to broadcast packet, the ttl must be equal to 1. ih->ttl()= 1; best regards > Subject: Re: [ns] Multihop Broacasting in ns2 > To: adel belkhiri <adel.belkh...@hotmail.com>, > ns-users@ISI.EDU > Message-ID: > <ae4085060910182048u52e0cb83y4ed8b03a7c4c5...@mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > Hi, > > I am trying to send broadcast packets from a node to its > neighbors.. Using > similar code as in below mail. But, after below statement, > c++ code is > throwing "Segmentation fault (core dumped)" error. > > Scheduler::instance().schedule(target_, p, 0); > > I am not able to atleast send broadcast packets to > neighbors. Please help me > understand the issue. did anyone have this issue? > > I commented above schedulercode and tried direct send() > function..like > "send(p,0);". This also gives same segmentation fault. > > I am attaching my tcl, .h & .cc files. I am new nsuser. > using ns2.34 with > cygwin in XP. > > Thanks for help in advance. > > On Thu, Oct 15, 2009 at 5:19 PM, adel belkhiri > <adel.belkh...@hotmail.com>wrote: > > > > > > > > > > > > > Hi my dears, > > > > I'm writing an agent that broadcast a packet to all > the neighbor nodes in > > the MANET network. I have search for a long time in > the net to do that with > > ns2 but I fail. In fact, the problem is that only > neighbors in the range of > > one hop from the sender node can receive the > packet!! The solution proposed > > for the broadcast problem by Jeff Bolen didn't resolve > the problem ( > > http://www.isi.edu/nsnam/archive/ns-users/webarch/2000/msg02832.html > ). In > > his proposition Jeff says that we should make a > duplicate the packet and > > send copy with the original packet up but I didn't > know how to do it :( ... > > I absolutely agree with Sanjay Raghani in its post ( > > http://www.mail-archive.com/ns-users@isi.edu/msg02771.html > ) when he says > > that the solution of Jeff is not the correct one for > many reasons but till > > now I don't have any idea how to proceed to solve my > problem :( > > > > My C++ function which I use to broadcast the > packet is below : > > > > void DistacAgent::broadcast_packet( ) > > { > > > > Packet *p = allocpkt(); > > if(p==NULL){ > > abort(); > > } > > > > hdr_cmn *ch = HDR_CMN(p); > > hdr_ip *ih = HDR_IP(p); > > > > //filling the Common header > > ch->ptype() = PT_DISTAC; // My agent packet > type !! > > ch->size() = IP_HDR_LEN + > sizeof(hdr_distac); > > ch->iface() = -2; > > ch->error() = 0; > > ch->addr_type() = NS_AF_NONE; > > ch->prev_hop_ = Agent::addr(); > > ch->next_hop() = IP_BROADCAST; > > ch->direction() = hdr_cmn::DOWN ; > > > > //filling the IP header > > ih->saddr() = Agent::addr(); > > ih->daddr() = IP_BROADCAST; > > > > ih->sport() = DISTAC_PORT; > > ih->dport() = DISTAC_PORT; > > > > ih->ttl_ = 32; > > > > // and finally sending the packet by putting it on the > scheduler > > Scheduler::instance().schedule(target_, p, 0); > > > > } > > > > Please if you have any idea don't hesitate to send to > me and thanks in > > advance !! > > > > Adel. _________________________________________________________________
