6RD
6to4
- The base standard
- Requires a specific prefix
6RD
- The current standard
- Allows any global prefix
RG — Router Gateway
- The CPE the ISP provides to connect to their network
BNG — Broadband Network Gateway
- This is the Customer aggregation node
- Aggregate thousands of connections
NMS — Network Management System
- Provides a place to see and configure the network
AAA — Authentication, Authorization, Accounting
- This is how the ISP controls who can access the network
- Controls QoS Deployments
BR
- Terminates the 6RD tunnels
- AKA, Border Relay
What does 6RD Solve?
“We can’t deploy v6, because our BNG does (put-feature-here) and we need that!
This way, the customer gets dual stack without the ISP needing to upgrade a legacy deployment.
The Four Things Required To Setup
- IPv4 Common Prefix: - The high order bits every CE has in common for their v4 deployments.
If every customer was given an IP on the 10.0.0.0/24 network, the bits they would have in common is /24.
- 6RD Prefix: The v6 bits for the 6rd domain.
- 6RD PrefixLen: The length of the prefix for the 6rd domain.
- 6RD BR v4 Address: The Access Network v4 address for the BR.
(there is a neat way to derive the 6rd prefix, refer to Cisco’s IOS-XE manual, that’s closest to how it’s done.)
Sample Config (from Cisco’s PDF)
!
! This BR is reachable via the loopback.
!
interface Loopback0
ip address 10.1.1.1 255.255.255.0
!
interface Tunnel0
tunnel source Loopback0
tunnel mode ipv6ip 6rd
tunnel 6rd ipv4 prefix-len 8
tunnel 6rd prefix 2011:1001:100:/40
ipv6 address 2011:1001:101:101::/128 anycast
!
ipv6 route 2011:1001:100::/40 Tunnel0
ipv6 route 2011:1001:101:101::/64 Null0
!
! Simple and Easy to setup!
!
#show tunnel 6rd
Interface Tunnel0:
Tunnel Source: 10.1.1.1
6RD: Operational, V6 Prefix: 2011:1001:100:/40
V4 Prefix, Length: 8, Value: 10.0.0.0
V4 Suffix, Length: 0, Value: 0.0.0.0
General Prefix: 2011:1001:1
References
RFC 3056: Connection of IPv6 Domains via IPv4 Clouds | RFC Editor
RFC 5969: IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) – Protocol Specification | RFC Editor
APNIC Conference | 6RD Enabling IPv6 Customers on an IPv4-only Network