21 Aug
2016
21 Aug
'16
5:34 p.m.
That "Requesting a Block" page has a lot of personal opinion it and also
contains directives that may
be valid for some regions but not for others. This already starts with the first line.
Here in the Netherlands we don't use the portal for requesting blocks, only for
registering blocks that are to be
used for IPIP tunnels. So requesting a block does not start with the portal, but with
mailing a request for a block
to me and allocation of the block in the hostsfile for 44.137.0.0/16 followed by updating
the DNS via the robot.
Once that is done, it can optionally be registered in the portal. I recommend users not
to do this unless they
want to setup a gateway, because registered subnets that are not claimed by a gateway are
up for grabs by
other gateway operators, and given that we have widely varying skills among out users it
has repeatedly happened
that users (who often not even understand what it means and requires to run an IPIP
gateway) create a gateway
entry and add someone else's subnet to it by mistake. This then cannot be corrected
by either the owner of
the subnet or the coordinator of the IP space. It requires a "contact the portal
admin" form entry to correct it
and that may take a long time to be acted upon. (I still have two open requests of that
type)
I also don't agree with the "don't waste space" adagium. I allocate
whatever is required for the experiment,
and now that we are using BGP internally on the radio network, that also includes /30 and
/29 networks for
point-to-point links (/30 for links with only a router at each end, /29 when it is desired
to have AP managment
addresses). Unlike on the internet, we have no lack of IPv4 space on AMPRnet!
There is no point in using RFC1918 addresses for this, and it causes problems with ICMP
messages returned
from those routers, e.g. when using traceroute. I also don't agree with "an ISP
uses unroutable addresses for
routers". Maybe some ISPs do that, but probably most do not.
About RFC1918 filtering: YES, everyone should filter RFC1918 addresses at every entry and
exit into the network.
There are many configuration mistakes in ham networks, and I often see log results on
those filters (which I
have configured with logging on our gateway). RFC1918 addresses come in via IPIP tunnels
from all over the
world and also from radio. Of course it requires detailed knowledge of networking,
policy routing, and NAT rules
to get a mixed net44/rfc1918 LAN correctly connected to AMPRnet (with NAT or blocking for
the RFC1918 systems)
and let's face it: many users simply don't have that knowledge and are just
trying.
So, everyone else should filter that traffic so that at least it does not get propagated
far. I sometimes send mail
to repeat offenders and they often promise me that they will look at it, but it rarely
stops completely.
Rob