Here, “KLM” has a slightly different meaning. “K” still means the SuperPoP, “L” means the PoP acting under the SuperPoP in an access network, and “M” is an identifier for the router in the PoP.

Loopback addresses are taken from the prefix:

2001:708:0:10:KLM::/112

So, a few loopback addresses will be:

tut0-rtr.funet.fi: 2001:708:0:10:300::1
tut1-rtr.funet.fi: 2001:708:0:10:301::1
uta3-rtr.funet.fi: 2001:708:0:10:313::1

These are configured using /128 prefix length. Note that the identifier of the router is also reflected in the naming (“uta_3_-rtr”).

Point-to-point addresses in the core and the access networks are taken from one block - all addresses come from under a single /64:

2001:708:0:F000::/64

In particular:

2001:0708:0:F000::klmn:KLMm:z/112

klm and KLM identify the routers at the end of the point-to-point links, taken from the loopback addresses; in above, these would have been “300”, “301”, and “313”. SuperPoP’s or the smallest number goes first as klm. “n” and “m” are sequential numbers, used when necessary - for example if there are multiple links between routers which need to be numbered - defaulting to zero. “z” is the end-point of the point-to-point link: always “1” or “2”. The same SuperPoP or smallest first rule applies here too. So, in consequence, the addressing becomes like:

uku0-jyu3: 2001:708:0:F000::4000:3230:[12]/112
uku0-oulu0: 2001:708:0:F000::4000:5000:[12]/112
uta3-jyu3: 2001:708:0:F000::3130:3230:[12]/112

The point-to-point links toward customers are always numbered from the customer’s addresses, due to simplicity and policy reasons.

For peerings and miscellaneous use, a block of:

2001:708:0:F001::/64

is reserved.

In addition, some special use addresses are used inside 2001:708::/48, for example 2001:708::{1,2} (for a few routers), 2001:708::123 (NTP), 2001:708::53 (DNS) etc.