IPv6 Multihoming
IPv6 Multihoming (Part 1 PI,PA and , Metro Addresss)
.. IPv6 does not have a set solution to the problem
.. IETF Working Group
.. multi6 WG
.. Activity in this group has been low
.. There have been over 40 Drafts proposed in the last five
years or so, but almost universally failed to reach RFC status
.. shim6 (Site Multihoming by IPv6 Intermediation) WG
.. Based on the architecture developed by IETF multi6 working group
.. Focus on IPv6-based site multi-homing solution that inserts a new sub-layer (shim) into the IP stack of end-system hosts
.. Locater-identifier approach looks likely to be adopted as a longer-term solution
Categories of Possible Approaches
- PI (Provider Independent) Addressing
End sites obtain IP address space independently from the providers
to which it is attached
These addresses might not be globally routable.
The solution may not scale to Internets
Notes
IPv6 為防止網際網路上的routing entries過多，目前
尚未開放End Sites使用PI addresses。
ARIN、RIPE及APNIC 都已有IPv6 PI Address Draft Policy提出討論，以暫時因應
用戶可能之需求及 IPv6推展之需要。
詳情請參考 TWNIC 6th OPM資料
-
PA (Provider Aggregatable) Addressing
End User轉到新Service Provider時，必須歸還給原 Service Provider
Using one ISP’s PA with a different ISP
Issues of ingress filtering
Deploy multiple prefixes delegated by ISPs
Possible Approaches
Routing
Mobility
New Protocol Element
Modify a Protocol Element
Modified Site-Exit Router interaction
-
Metro Addressing
An address prefix is assigned to a
suitable regional authority such as acity
The authority :
Assigns small (/64, /60, /56) prefixes to
smaller entities in
the region
Obtains agreements from the ISPs to use
those prefixes for their
multihomed
customers and route among themselves for
other customers
Only the larger prefix is advertised outside
the region
Possible implementation
All the ISPs maintain bilateral contracts and exchange
more specific route with each other, or
All of the ISPs contract with a routing exchange point
operated by the regional authority
In Metro model, traffic is carried by sender’s ISP
to the region and transits to the destination ISP
There is an implied transit model that has to be accounted
for
New ISP buys transit from all others?
Some form of transit cost settlements between ISPs?
MY Notes BLOG 