Hi,
86.161.255.194 is the destination for 44.131.14.128/26. Just to
clarify, what you were seeing was probably stray traffic from an IPv6
tunnel which goes between my 44net addresses. Blame the main BT router
not handling IPv6 encapsulated packets unless I stick an extra IPv4
header on. Normally my traffic should not traverse the gateway, but
over the last couple of days I have been testing a backup system for
when my BGP routes go down so you probably saw some stray packets
reach the main gateway during last nights tests. If you happened to
capture the inner and outer headers and it shows something other than
an IPv6 encapsulated packet with a destination inside 44.131.14/24, or
if you are seeing traffic whilst my BGP route is up then it might be a
configuration error.
Regarding the other thread about which firewall rules to use, the
gateway is a little more complicated but for my home router I
(normally, not last night in case you saw differently) have the
equivalent to:
iptables -t filter -A FORWARD -i tunl0 ! -d 44.131.14.128/26 -j REJECT
iptables -t filter -A FORWARD -o tunl0 ! -s 44.131.14.128/26 -j REJECT
I think this pretty much covers the requirements for a basic end network?
If the main gateway receives an invalid encapsulated packet from a
known gateway or a 44net address, would it be helpful to return an
error instead of dropping it? An ICMP Administratively Denied packet
is more likely to generate an obvious error message than packets going
missing. The gateway would probably need to rate-limit the number of
errors it will send out to prevent abuse, though.
Thanks,
Mike, M6XCV
On 20 April 2017 at 00:39, Brian Kantor <Brian(a)ucsd.edu> wrote:
(Please trim inclusions from previous messages)
_______________________________________________
In our tunnels, all traffic from a gateway should be encapsulated
and should NOT contain an encapsulated ipencap packet. The ipip
router at UCSD logs and discards these; I'm seeing such packets
from gateways
77.138.34.39
85.234.252.133
86.161.255.194
185.58.225.84
which suggests that they have a routing misconfiguration. The
operators of those gateways should examine their routing and
encapsulation rules to see why this is happening.
- Brian
_________________________________________
44Net mailing list
44Net(a)hamradio.ucsd.edu
https://u4477715.ct.sendgrid.net/wf/click?upn=vS4GjSiF-2F5vYmfX5tr6ez81-2Fe…