Retrospect on the Hype of Locator/ID Separation and its Fallacies.

1. Some Thoughts on
Loc/ID Separation
DaeYoung Kim
dykim@cnu.kr

2. Questions
• Is LIS properly positioned?
• Any insights to a better network architecture?

3. IAB Routing & Addressing
Workshop 2006
• Explosion of DFZ routing table
• << Incompetence of multi-homing
• << Semantic overloading of IP address
• >> Separation of Loc and ID

4. Semantic Overloading
Host
IP address
id
locator

5. Loc/ID Separation (LIS)
Host
Loc
ID

6. Migration
ISP1
nw prefix subnet host i/faddr

7. Migration
*losing all sever connections at transition
renumbering*
ISP2
nw prefix subnet host i/faddr

8. Multi-homing
*Competing for more specific prefixes into DFZ
backup
major
ISP1
ISP2
*You want PI addr

9. Loc doesn't help
• Same fate as IP address
• Renumbering at migration
• Tend to be injected into DFZ
• Doesn't help mitigate table explosion
• LIS, not a solution to the problem

10. Fallacy of IP address
Host
IP address
PoA*
MAC address
L2
L3
*Naming the same leg twice

11. Fallacy of IP address
H
C
X
?

12. Different Locators
Host
LISP
ILNP
subnet
site
subnet
subnet
HIP

13. What's up?
• Loc/ID separation?
• Recursive addressing?
• host addr - subnet addr - site addr

14. Norms…?
• Shach[’78]
• name(what), address(where), route(how)
• Saltzer[’78 & rfc1498]
• service, node, PoA, route

15. Links first

16. Links first

17. Links first

18. Links first

19. Nodes first

20. Nodes first

21. LISP EID
• IP address? ... !
• Flat? ... !
• Static? ... !
• Globally unique? ... !
• no changes in host behaviour? ... !

22. if EID = IP address
• Not flat
• hierarchically assigned PoA address
• changes as PoA changes
• Not globally unique
• need a new EID at migration to a new LISP site
• Semantically overloaded

23. Let EID == node ID
• Pointing to the node(host, router; system)
• not to the interface
• Use ISIS for IGP, and
• In-site host/subnet mobility, a default
• no need for Mobile IP

24. ISIS
H
subnet
subnet
subnet
R
Area Sys IDaddr
Area

25. EID global?
Why not local?
• Name already global
• Server identified by a name
• name <-> [RLOC + (local) EID]
• Client given a temporary id anyway; DHCP

26. Recursive Addressing
tier 0 tier +1 tier +2tier -1
EID RLOC ??
Name

27. Any insights to a better
network architecture?

28. Merci!