gesh75 IPv6 dual-stack
Do not use for IPv4-only RFC1918 cleanup. Not for application socket code.
Procedure
- Address plan: /48 per site, /64 per VLAN, GUA from the ISP plus ULA for internal-only. No IPv4-think /127 on p2p unless the platform needs it.
- RA on access, not on routed p2p. Enable RA guard and DHCP-Guard on campus.
- Dual-stack BGP with a separate IPv6 AF. Do not carry v6 over v4 6PE unless the core cannot.
- Prefer native end-to-end. NAT64 only for broken SaaS. Document DNS64.
- Verify: ping6 to the default GW, traceroute6 off-net, and a v6-only test host.
vlan 24
ipv6 address 2001:db8:24:24::1/64
ipv6 nd ra hop-limit 64
ipv6 nd raguard
Anti-patterns
- Never put GUA on a management VRF that should be ULA-only.
- Do not disable RA to "stop the noise" — fix the flood.
Safety
RA and prefix changes are change-guarded. A bad RA takes the campus down.