New subject: Time to restructure the network?

22 Jul 2019


      ...
Personally, I love the idea of allowing the network to be more
inclusive by allowing connections other than the current IPIP one. 
Rather than replace IPIP, I would suggest that we keep it and just allow 
people to act as hubs for those that are behind NAT/Limiting firewalls, etc.
This is what we already have working, and others have that too.  A local 
VPN server that is connected to IPIP (and in our case BGP too).
However, such a setup is a bit complicated because the IPIP mesh is not 
well supported on many router types, and having the two
different network types integrated in the same router also is kind of 
tricky.
Not everyone gets that right: all routes have to be in the same routing 
table and evaluated from more-specific to less-specific.
But you still need to handle cases where multiple routes to the same 
subnet (using different protocols) can exist.
In some cases, people have resorted to having multiple routing tables 
and searching them in a specific sequence, but that does not work 
correctly in some cases.
Also there is the issue of determining the correct source address. 
Sometimes such gateways send traffic with a non-44net source address 
through an IPIP tunnel, which of course is unwanted.
So my proposal is to drop the IPIP mesh to remove this additional 
complexity, and make the system easier to rollout and maintain.
...
While I think BGP would be great, it adds questions like: can people
announce their own non-44 space, can people use their own ASNs, how will 
we allocate ASNs, how do we confirm people are announcing space actually 
allocated to them. One thing we can do, is look at DN42 and how they 
work. Their network is similar to some of these suggestion with the 
exception that they use private space.
Some of those topics have already been addressed and resolved before.
For example w.r.t. the AS numbers, we have agreed to use an allocation 
scheme for private AS numbers so this can be delegated to individual 
regions without chance of collisions.
The scheme is to use "42"+iso country designator+5 digits, where these 5 
digits can be subdivided in a region specific way.
Large countries have several iso country designators so there should be 
ample space using this scheme.
Here we use 42204+3digits+2digits where a router in our 
44.137.aaa.bbb/16 subnet gets AS 44204aaann where nn=bbb/16.
Of course this network is only meant to distribute net44 addresses, our 
routefilters filter announcements outside that.  But you can announce 
space for your friend inside net44.   Actually the same as the current 
IPIP situation.
Indeed very similar to what DN42 does.
Rob

Re: [44net] Time to restructure the network?