Thank you for favor. I solve the problem from your advice. "you'll also need to rewrite the SRC when sending from B back to A"
And OFPAT_SET_NW_DST update*automatically *the IP checksum. I didn't notice it. Thanks a lot! - Hyogi 2012/1/9 Murphy McCauley <jam...@nau.edu> > OFPAT_SET_NW_DST should update the IP checksum. Are you sure that a bad > checksum is the problem? > > Remember that if you rewrite the DST when sending from A to B, you'll also > need to rewrite the SRC when sending from B back to A. Host A doesn't know > that you've rewritten the address and will have no idea that a message from > some arbitrary address is supposed to be from B! > > As a sidenote, you seem to be reading from the OpenFlow 1.1 spec, but NOX > currently only supports OpenFlow 1.0. > > -- Murphy > > On Jan 9, 2012, at 4:08 AM, Hyogi Jung wrote: > > > Hi, > > > > I want to change the destination address. > > So I use these actions. And add output action. > > > > OFPAT_SET_DL_DST, /* Ethernet destination address. */ > > OFPAT_SET_NW_DST, /* IP destination address. */ > > > > Finally destination node could receive the changed packet. > > > > But there is a problem. > > I snoop the packets using wireshark. After 3-handshaking (SYN, SYN+ACK), > the sender node send "RST" packet. > > I think it is occured by reason of "I didn't update the IP checksum." > > > > Openflow-spec describe below. > > > > Action : Set IPv4 destination address > > Description : Replace the existing IP destination address with and > update the IP checksum (and TCP/UDP/SCTP checksum if applicable). > > This action is only applied to IPv4 packets. > > > > But How can I update the IP checksum? > > I use C/C++ languge. I try to find updating IP checksum problem in > nox-mailing list. > > But I couldn't find it. > > > > Is it a possible using "send_openflow_command()" fuction or > "send_openflow_packet()" fuction? > > > > send_openflow_command() function = change original packet in switch > using flow action. > > however, send_openflow_packet() = send new packet instructed by > controller. > > > > Could you give some advice or reference source? > > > > Thank you. > > > > - Hyogi > > _______________________________________________ > > nox-dev mailing list > > nox-dev@noxrepo.org > > http://noxrepo.org/mailman/listinfo/nox-dev > > -- Hyogi Jung, MS Student Multimedia & Mobile Communications Lab School of Computer Science and Engineering Seoul National University, Korea Tel: +82-2-880-9147
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