IPNL: A NATExtended Internet Architecture

1
IPNL A NAT-Extended Internet Architecture

• Francis Gummadi
• Riku Honkanen

2
NAT basics

• Network Address Translation
• Pros
• Expands IPv4 address space
• Isolates private network address space from
  global address space
• Cons
• Unaddressable hosts
• Complicates scalable network operation

3
IP Next Layer major attributes

• Infrastructure reuse
• Changes only to hosts NAT boxes
• FQDN Utilization
• Fully qualified domain name as the main
  identifier
• Extended IP address space
• Isolated site addressing
• Global addresses do not show in internal site
  routing

4
IPv4 ? IPNL
5
IPNL example
6
IPNL address

• MRIP Middle Realm IP address
• globally unique IP address of a frontdoor
• RN Realm Number
• Realm number assigned by a frontdoor or a site
• EHIP End Host IP
• private IP address inside a realm

7
IPNL Header Format

• Separate local and global header
• Global header is not used for local packets
• Global header must be attached if FQDN header is
  attached

8
Connection states

• In the beginning host knows
• Own FQDN
• Own EHIP
• Destination FQDN
• Session initiation by DNS lookup
• Random ID (RID) for each connection
• Maintained variables for each global connection
• next-hop value
• List of MRIPs for the destination
• List of MRIPRN combinations for the destination
• Latest MRIPRN combination used

9
Seminar theme related

• ID/Locator split
• FQDN mainly identifier but also locator
• IPNL address mainly locator but also short-term
  identifier
• Might work together with HIP
• IPNL addresses can change dynamically during the
  connection while FQDN stays the same
• Multi-homing by isolated site addressing

10
Conclusions

• Strengths
• Extends IPv4 addressing effectively
• Good scalability
• Support for dynamic address changes and
  multi-homing
• Question marks
• Neighbor pinging
• Hijack resistance mechanisms