[afripv6-discuss] Agrigation with IPv6

[Mark J Elkins]

Posix Systems was recently allocated some IPv6/32

I'm trying to understand how I can best meet both customer needs whilst 
keeping good aggregation and have come up with the following:

1)  I get assigned a /32 (2001:42a0::) - where '42a0' is what ever is 
assigned (ok - what Posix was assigned!)

2) I am more or less expected to assign /48's to customers..
..which generally leaves 16 bits to assign to customers


My goal is to aggregate as much as possible - whilst learning from past 
"mistakes".

It would therefore seem a reasonable thing to split these 16 bits into 
something like 6 and 10. The first 6 bits (64 permutations) then becomes 
a logical geographical area - eg. Joburg, Cape Town, Swaziland - etc. 
and the last 10 bits (1024 permutations) becomes a customer in that 
area. This way - if the Cape Town peering point is ever re-resurrected, 
I can use a single net-mask (ie Route) to advertise all my Cape Town 
clients to that peering center. I might in fact reserve more than one 
set of 6 bits for the Johannesburg area (ie - 4 bits for the area and 12 
bits for customers) - but that would probably be the only variation.
I'm currently using 4bits for an area and the remainder for customers. 
I'm also using a /48 in each area for internal use (ie - local hosting, 
dial-up - etc), so if I loose long distant links - all the 'local' stuff 
would still work / be accessable.

As far as I can see - many LIR's simply allocate the next logical /48 
block to the next customer and disregard any possibility of 
regionalising IPv6 addresses.

What do others think? Anything better?

                 ----------------------------------------------------------

Posix Systems (like other IPS's)  does customer hosting of machines, 
many of which need multiple IP addresses for different SSL sites - etc. 
An assumption is that most people would allocate a full /64 to an 
Ethernet interface.

The simple mapping of a MAC address to the Host portion (ie - the last 
64bits) of an IPv6 address does not allow for the easy addition of 
multiple IP's on the same machine. It does however make scanning a /64 
difficult - unless you know that the hosting company only uses one 
particular brand of Ethernet card.

Given a MAC address of:   00:0D:56:FE:CB:08,  (which auto 
becomes...::020d:56ff:fefe:cb08) I propose to turn this into....
...:56fe:cb08:MMMM:NNNN.
NNNN would be a simple sequence number (from 0 or 1 upwards) [I have 
noticed that providing a range of IPv6 addresses on a Linux machine ie...
config_eth1=( "192.96.28.{1..9}/24"
        "2001:668:0:3::4000:{0092..0099}/124"
)
.... only works for decimal values - it chokes on Hex  values (A-F)]

The MMMM could map to a security map of what ports that IP address 
should be allowed to accept......
The 16 bits could be defines as...

1 - ssh (port 22)
2 - web (port 80)
3 - ssl web (443)
4 - pop3 ( both 110 and 195)
5 - imap (both 143, 220 and 993)
...
F - anything (no auto firewall)

..thus a value of :0: would not allow the (upstream) firewall  to send 
through anything, but a value of :ffff: would allow everything 
through..  thus a hosting client could define for themselves what ports 
the firewall would let through...

I'd then use a common set of filter lists on my firewall - just to look 
at those bits - for the majority of customers. There will always be 
exceptions to some customers - but this can be handled in the 
traditional way.

Anyone done anything like this?
Other Suggestions?

-- 
  .  .     ___. .__      Posix Systems - Sth Africa
 /| /|       / /__       mje at posix.co.za  -  Mark J Elkins, SCO ACE, Cisco CCIE
/ |/ |ARK \_/ /__ LKINS  Tel: +27 12 807 0590  Cell: +27 82 601 0496