I have some trouble with understanding of IPv6 6to4:
In the specific when I send a IPv6 packet to an IPv4 cloud toward a 6to4 destination address, the packet will encapsulated with protocol type 41 (usefull if i have an ACL) and then prepended to IPv6 packet. Now the intial packet who I sent It will route across the 6to4 tunnel, at this time the router extracts the IPv4 address embedded in the IPv6 address (end point tunnel remote) and will use it for build the IPv4 destination address of the tunnel header. I begin my configuration: Now R3 (both border router facing Ipv4 cloud and IPv6 client) send a packet, It will match routing table and my routing table is ::/0 across interface tunnel Ipv6. I am thinking here is where 6to4 come in play, the initial packet IPv6 will encapsulated in IPv4; furthemore the new source for the outer packet is taken from tunnel source; now I'am going to ask your help, my doubt how r3 calculate next hop address if 6to4 treats cloud IPv4 as monolithic NBMA non-broadcast? Perhaps is taken and converted from end point of tunnel's? In fact my next hop is tunnel345 not specific next hop. However how did to decide which Next Hop if I have more as in this case: r3-r4-r5? I thought that it taken from route for some specific next hop, or something like that.... In fact my test coinvolve loopback both to r3 and r4 and ping from r3 toward r4 across tunnl Ipv6 6TO4. to have successfull ping I have done some trucks namely with two approach, neverthless let me know if I'am wrong. I have add specific and second route for ipv6 destination to r3, hence ipv6 destination will be 2001:cc1e:0:0::/64 next hop of R4. At this time precedent next hop will be recursive toward ::/0 t345 hence I have the closest and only route is versus tunnel345, I suppose it will converted in IPv4 using some reverse logic and try to reach to R4, finally :-) My second method has been ipv6 route ::/0 t345 in the same line add next hop of R4. In effect both solution work well. Any feedback will be appreciated. Sorry I have written any twaddle and I hope that my E-mail is clear, I am not a native english speaker. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
