IPV6 LAN not routing to WAN

[exulan]

My router is able to ping the internet via IPV6

exulanit-router#ping 2606:4700:4700::1111
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2606:4700:4700::1111, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms

My devices can ping the router IPV6 address

exulan@server1:~$ ping 2001:DB8:85A3:1::1
PING 2001:DB8:85A3:1::1(2001:db8:85a3:1::1) 56 data bytes
64 bytes from 2001:db8:85a3:1::1: icmp_seq=1 ttl=64 time=3.27 ms
64 bytes from 2001:db8:85a3:1::1: icmp_seq=2 ttl=64 time=0.700 ms
64 bytes from 2001:db8:85a3:1::1: icmp_seq=3 ttl=64 time=0.695 ms
64 bytes from 2001:db8:85a3:1::1: icmp_seq=4 ttl=64 time=0.657 ms

But my devices cannot ping the internet via IPV6

exulan@server1:~$ ping 2606:4700:4700::1111
PING 2606:4700:4700::1111(2606:4700:4700::1111) 56 data bytes
^C
--- 2606:4700:4700::1111 ping statistics ---
22 packets transmitted, 0 received, 100% packet loss, time 21491ms

Ive been looking into this for hours but cannot get it to work.

This is my full running-config
https://termbin.com/45ep

[balaji.bandi]

interface GigabitEthernet0/0/0
 ip address dhcp
 ip nat outside
 media-type rj45
 negotiation auto
 ipv6 address dhcp
 ipv6 address autoconfig default

what is the IP address you get from ISP  IPV6 or IPV6  - based on that you need to have NAT

if you getting IPv4 you need NAT64 translation required.

also check default route you getting from DHCP ?

check some NAT64 examples :

https://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/217208-understanding-nat64-and-its-configuratio.html

[Harold Ritter · Accepted solution]

Hi @exulan ,

Using the documentation prefix "2001:db8::/32" will not work. You need to use a routable prefix.

You can use DHCPv6 prefix delegation to get a prefix from the ISP. Try the following configuration.

interface GigabitEthernet0/0/0
 ipv6 address dhcp
 ipv6 address autoconfig default
 ipv6 dhcp client pd prefix-from-provider

interface GigabitEthernet0/0/1
ipv6 address prefix-from-provider ::1:0:0:0:1/64

 Regards,

[exulan]

Thank you, ipv6 internet connectivity its now working on devices connected to my g0/0/1 interface but the devices on the vlan 88 g0/0/1.88 interface are not getting an IPV6 address.

ipv6 unicast-routing
ipv6 dhcp pool Server_Network_IPV6
prefix-delegation pool prefix-from-provider
dns-server 2606:4700:4700::1111
!
ipv6 dhcp pool Main_Network_IPV6
prefix-delegation pool prefix-from-provider
dns-server 2606:4700:4700::1111
!
interface GigabitEthernet0/0/0
ipv6 address dhcp
ipv6 address autoconfig default
ipv6 enable
ipv6 dhcp client pd prefix-from-provider
!
interface GigabitEthernet0/0/1
ipv6 address prefix-from-provider ::15:1/64
ipv6 enable
ipv6 dhcp server Main_Network_IPV6
!
interface GigabitEthernet0/0/1.88
encapsulation dot1Q 88
ipv6 address prefix-from-provider ::88:1/64
ipv6 enable
ipv6 dhcp server Server_Network_IPV6

[Harold Ritter]

Hi @exulan ,

I am glad to hear it is now partially working.

You have both gi0/0/1 and gi0/0/1.88 using the same /64 at the moment (prefix-from-provider ::/64), hence it does not work for gi0/0/1.88.

Try the following instead:

int gi0/0/1

ipv6 address prefix-from-provider ::15:0:0:0:1/64

int gi0/0/1.88

ipv6 address prefix-from-provider ::88:0:0:0:1/64

Can you also provide the output for "show ipv6 general-prefix"?

Regards,

[exulan]

exulanit-router(config-subif)#do show ipv6 general-prefix
IPv6 Prefix prefix-from-provider, acquired via DHCP PD
2403:5814:F0B1::/48 Valid lifetime 5719, preferred lifetime 2118
GigabitEthernet0/0/1 (Address command)
GigabitEthernet0/0/1.88 (Address command)

exulanit-router(config-subif)#do show ipv6 int gi0/0/1.88
GigabitEthernet0/0/1.88 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::56A2:74FF:FE64:CA61
No Virtual link-local address(es):
General-prefix in use for addressing
No global unicast address is configured
Joined group address(es):
FF02::1
FF02::2
FF02::1:2
FF02::1:FF64:CA61
FF05::1:3
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.

GigabitEthernet0/0/1.88 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::56A2:74FF:FE64:CA61
No Virtual link-local address(es):
General-prefix in use for addressing
No global unicast address is configured 

[Harold Ritter]

Hi @exulan ,

The issue is exactly what I explained in my previous post. gi0/0/1.88 does not have an ipv6 address because ::15:1 and ::88:1 are actually part of the same /64, hence gi0/0/1.88 not being configured with a global unicast ipv6 address.

The following should work for you:

int gi0/0/1

ipv6 address prefix-from-provider ::15:0:0:0:1/64

int gi0/0/1.88

ipv6 address prefix-from-provider ::88:0:0:0:1/64

Regards,

[exulan]

So I changed it to what you said and it still wasnt working, All devices lost connectivity to the internet via ipv6

interface GigabitEthernet0/0/1
ipv6 address prefix-from-provider ::15:0:0:0:1/64
ipv6 enable
ipv6 nd autoconfig prefix
ipv6 dhcp server Main_Network_IPV6
!
interface GigabitEthernet0/0/1.88
encapsulation dot1Q 88
ipv6 address prefix-from-provider ::88:0:0:0:1/64
ipv6 enable
ipv6 nd autoconfig prefix
ipv6 dhcp server Server_Network_IPV6

So I did this

interface GigabitEthernet0/0/1
ipv6 address prefix-from-provider ::15:1/64
ipv6 enable
ipv6 nd autoconfig prefix
ipv6 dhcp server Main_Network_IPV6
!
interface GigabitEthernet0/0/1.88
encapsulation dot1Q 88
ipv6 address 2403:5814:F0B1:88::1/64
ipv6 enable
ipv6 nd autoconfig prefix
ipv6 dhcp server Server_Network_IPV6

and now everything is working! Thank you for your help.

[Harold Ritter]

Hi @exulan ,

The configuration you provided is static and might not work over time.

Can you please provide a "show ipv6 int gi0/0/1" and "show ipv6 int gi0/0/1.88" with the configuration I provided?

Regards,

[exulan]

I see, I reverted it back to what you recommended.

exulanit-router#show ipv6 int gi0/0/1
GigabitEthernet0/0/1 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::56A2:74FF:FE64:CA61
No Virtual link-local address(es):
General-prefix in use for addressing
Global unicast address(es):
2403:5814:F0B1:15::1, subnet is 2403:5814:F0B1:15::/64 [CAL/PRE]
valid lifetime 7077 preferred lifetime 3476
Joined group address(es):
FF02::1
FF02::2
FF02::1:2
FF02::1:FF00:1
FF02::1:FF64:CA61
FF05::1:3
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.

exulanit-router#show ipv6 int gi0/0/1.88
GigabitEthernet0/0/1.88 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::56A2:74FF:FE64:CA61
No Virtual link-local address(es):
General-prefix in use for addressing
Global unicast address(es):
2403:5814:F0B1:88::1, subnet is 2403:5814:F0B1:88::/64 [CAL/PRE]
valid lifetime 7068 preferred lifetime 3467
Joined group address(es):
FF02::1
FF02::2
FF02::1:2
FF02::1:FF00:1
FF02::1:FF64:CA61
FF05::1:3
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.

[Harold Ritter]

Hi @exulan ,

This looks good. Both gi0/0/1 and gi0/0/1.88 have their own /64. Can you test again to check that it works.

Regards,

[exulan]

MY BAD! I had to renew the ipv6 release on the device to get it to work, my apologies for that. Its all working now thank you!

[syaifulnizamshamsudin]

Hallo,please support and share for me access back ipV6 network Cisco Group.