Lab 9: Dual-Stack IPv4/IPv6 Addressing on IOS

Bundle lab · $29.99

Configure and verify dual-stack IPv4 and IPv6 addressing on Cisco IOS router interfaces. R1-R2 share a /30 IPv4 and /64 IPv6 point-to-point transit, while R1 provides a dual-stack user LAN gateway. No routing protocols or router static routes are permitted; verify only directly connected reachability.

Learning objectives

• Explain dual-stack operation and why both IPv4 and IPv6 can coexist on the same interface
• Configure IPv4 addresses with dotted-decimal masks and IPv6 global unicast addresses with /64 on IOS
• Enable IPv6 forwarding with ipv6 unicast-routing
• Bring interfaces up and verify addressing using show ip interface brief and show ipv6 interface brief
• Validate directly connected IPv4 and IPv6 reachability without any routing protocols or router static routes

Troubleshooting focus

• Interface is administratively down: ensure no shutdown on each addressed interface
• IPv6 not forwarding: ensure ipv6 unicast-routing is enabled on each router
• Mask/prefix mismatch on a point-to-point: verify 255.255.255.252 for the /30 and /64 on both ends
• Typos in addresses cause duplicate or out-of-subnet IPs: check exact values and neighbor IPs
• Host default gateway wrong: confirm 192.168.100.1 and 2001:db8:100::1 on clients