DEAR sir, Now I encountered a problem with umip-dsmip's BU encapsulation. As implemented in Dsmip, if MN is running on a ipv4 network and gets a new ipv4 coa, it will set up its xfrm states and policies for UDP encapsulation of BU messages, and finally the BU message is encapsulated with UDP and sent to HA directly. However, I found that sometimes the BU messages are encapsulated with UDP and enter the ipip tunnel before they are sent to HA.
The encapsulated packet will be in this way: -----ipv4 destination address(HA's address)---- -----ipv4 source address(MN's coa address) ---- -----ipv4 destination address(HA's address)---- -----ipv4 source address(MN's coa address)----- ------ipv4 UDP header-------------------------- ------ipv6 BU messaege------------------------- As we know, ipip tunnel encapsulated packet will not traverse NAT(it will be dropped by the NAT gateway and returned an error ICMP message called "protocol not reachable") , and when the scenario described above happens, the UDP encapsulation becomes useless. I have noticed that when such error happens, the state and policies of xfrm, the ip routing rules(with command "ip -6 rule" or "ip rule"), and ipv4 or ipv6 routing tables are all the same as those ones when BU are correctly encapsulated(not go into ipip tunnel). I am wondering if there are some place in xfrm to specify which egress interface it should use? and the reason with the problem described above? Or how to resolve the problem? Thank you very much. Yours sincerely, Hui. -- 林辉 中科院计算技术研究所 _______________________________________________ Dsmip mailing list [email protected] http://ml.nautilus6.org/mailman/listinfo/dsmip
