IPv6 Setup — Cisco (IOS-XE 17.x)

This guide covers how to configure IPv6 with prefix delegation on Cisco IOS-XE 17.x routers for use with Zal Ultra ISP CRM.

⚠️ PREREQUISITES

• Cisco router running IOS-XE 17.x or later
• PPPoE server already configured and working with IPv4
• RADIUS client configured and connected to Zal Ultra
• Valid IPv6 prefix allocated from your upstream provider
• Backup your router configuration before making changes

Architecture

Subscriber CPE (DHCPv6-PD Client)
    ↓
Cisco Router (BNG / PPPoE Server + RADIUS Client)
    ↓
Zal Ultra (RADIUS Server + Billing)

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Step 1: Enable IPv6 Routing

! Enable IPv6 unicast routing globally
configure terminal
ipv6 unicast-routing
ipv6 cef

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Step 2: Create IPv6 Local Pool

! Create an IPv6 local pool for prefix delegation
ipv6 local pool IPV6-PD-POOL 2001:db8:1000::/40 56

! Verify the pool
show ipv6 local pool

Parameter	Description
IPV6-PD-POOL	Name of the IPv6 pool
2001:db8:1000::/40	Your allocated IPv6 prefix
56	Prefix length delegated to each subscriber

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Step 3: Configure DHCPv6 Pool

! Create DHCPv6 pool for subscriber prefix delegation
ipv6 dhcp pool IPV6-SUBSCRIBER-POOL
  prefix-delegation pool IPV6-PD-POOL
  dns-server 2001:4860:4860::8888
  dns-server 2001:4860:4860::8844
  domain-name yourisp.com

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Step 4: Configure Virtual Template with IPv6

! Update virtual template for PPPoE with IPv6 support
interface Virtual-Template1
  ip unnumbered Loopback0
  ipv6 enable
  ipv6 dhcp server IPV6-SUBSCRIBER-POOL
  ipv6 nd ra interval 30
  ipv6 nd managed-config-flag
  ipv6 nd other-config-flag
  peer default ip address pool PPPoE-POOL
  ppp authentication chap callin
  ppp authorization radius

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Step 5: Configure RADIUS for IPv6

! Ensure AAA is configured with IPv6 attributes
aaa new-model
aaa authentication ppp default group radius
aaa authorization network default group radius
aaa accounting network default start-stop group radius

! RADIUS server configuration
radius server ZAL-ULTRA
  address ipv4 <ZAL_ULTRA_IP> auth-port 1812 acct-port 1813
  key <YOUR_RADIUS_SECRET>

! Enable IPv6 attributes in RADIUS
radius-server attribute 6 on-for-login-auth
radius-server attribute 97 include-in-access-req

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Step 6: Configure IPv6 on WAN Interface

! Assign IPv6 address to WAN / upstream interface
interface GigabitEthernet0/0
  ipv6 address 2001:db8::1/64
  ipv6 enable
  no shutdown

! Add default IPv6 route
ipv6 route ::/0 2001:db8::ffff

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Step 7: Verify Configuration

! Check IPv6 interfaces
show ipv6 interface brief

! Check IPv6 routing table
show ipv6 route

! Check active PPPoE sessions
show pppoe session

! Check DHCPv6 bindings
show ipv6 dhcp binding

! Check IPv6 pool usage
show ipv6 local pool

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Quick Reference

Task	Command
Check IPv6 interfaces	show ipv6 interface brief
Check IPv6 routes	show ipv6 route
Check PPPoE sessions	show pppoe session
Check DHCPv6 bindings	show ipv6 dhcp binding
Check IPv6 pool	show ipv6 local pool
Save configuration	write memory

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Need Help?

If you need assistance with Cisco IPv6 configuration, please contact Onezeroart Support.