[Jool-list] returned IPv6 packets

[Michael Richardson]

Alberto Leiva <ydahhrk at gmail.com> wrote:
    >> I have a scenario where I'm trying to use Jool along with an
    >> IP6-in-IPv4 (ESP/IPsec) tunnel.

    > Ok; as long as the packet is decrypted before reaching Jool I don't
    > think there's anything strange about this.

    >> Packet #2 is odd, and something I'm investigating on the tcpdump side
    >> of things; it's the the IP6 packet coming out of the tunnel.

    > I'm not very familiarized with the IPSec protocol, but if you dump this
    > into a pcap file, maybe I can help with this.

I will definitely may do this, as it it will become a test case for tcpdump.
[just so you realize I'm the tcpdump maintainer :-)]

    >> I can't see why it would be fragmented, given that it's 64-bytes.
    >> Bug?

    > Yes, sort of: It's an atomic fragment
    > (https://www.jool.mx/usr-flags-atomic.html). Jool felt the need to
    > include a redundant fragment header because of a combination of the DF
    > flag and the packet length. It's something RFC 6145 wants but it's
    > currently being deprecated.

    > Indeed, Jool 3.3 catched up with this fact and handles atomic fragments
    > better (by which I mean, it avoids them). It you upgrade, the redundant
    > fragment header should go away.

Thanks, I haven't gotten to the update process, maybe later this afternoon.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mcr at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [