PPP over IPv6

[FlorianViaN]

Hello,

I'm trying to configure PPPoE in IPv6 on a Cisco Router 7301 (without RADIUS) but it doesn't send DNS(ip name-server) and an IPv6 configuration from the pool (Windows 7).

I tried in IPv4, and everything worked.

VLANs

2 : fd01::120:0/112

96 : fd01::96:0/112

120 :fd01::120:0/112

This is an IPv6 Test network

Thanks.

My network

Router

aaa new-model
pppoe-forwarding
ip cef
!
ip domain name server1.stageipv6.com
ip name-server fd01::120:53
ip ssh version 2
ipv6 unicast-routing
ipv6 cef
!
username test password 7 06120A3258
!
bba-group pppoe stag_pppoe
 virtual-template 1
 sessions per-mac limit 2
!
interface GigabitEthernet0/0
 description VLAN 2
 ip address 80.245.16.27 255.255.255.128
 duplex auto
 speed auto
 media-type rj45
 no negotiation auto
 ipv6 address FD01::2:1000/112
 ipv6 enable
!
interface GigabitEthernet0/1
 description VLAN 96
 ip address 192.168.96.27 255.255.255.0
 duplex auto
 speed auto
 media-type rj45
 no negotiation auto
 ipv6 address FD01::96:1/112
 ipv6 enable
 pppoe enable group stag_pppoe
!
interface Virtual-Template1
 description pppoe bba1
 no ip address
 ipv6 address autoconfig
 ipv6 enable
 ipv6 mtu 1492
 no peer default ip address
 peer default ipv6 pool pool_pppoe
 ppp authentication chap callin
!
ipv6 route FD01::120:0/112 FD01::2:2
ipv6 local pool pool_pppoe FD01::96:0/112 114

ipconfig /all

No field IPv6 address
Just IPv6 link local : fe80:....
DNS : fec0:0:0:0:ffff::1%1
 fec0:0:0:0:ffff::2%1
 fec0:0:0:0:ffff::3%1

[Harold Ritter]

Hi Florian,

A couple of things.

- Configure a /64 on the pool instead of a /112. Only /64 works for SLAAC.

ipv6 local pool pool_pppoe FD01::0/56 64

- Unlike ipcp, ipv6cp does not supply DNS information. You need to configure stateless DHCP in order for the host to learn the DNS automatically. 
 

ipv6 dhcp pool test

dns-server 2001:db8:1:1::1

interface Virtual-Template1 
 ipv6 nd other-config-flag 
 ipv6 dhcp server test

Regards

[FlorianViaN]

Hello,

Thanks, but it doesn't work too with your configuration.

I don't know what and where is the real problem.

Regards

[Harold Ritter · Accepted solution]

Hi Florian,

There are a few things missing.

- Configure a loopback interface with an IPv6 address.

- Change your "ipv6 address autoconfig" on the virtual-template1 for "ipv6 unnumbered Loopback0".

- Add "no ipv6 nd ra suppress" on virtual-template1.

interface Loopback0

ipv6 address 2001:DB8:12FF::1/128

!

interface Virtual-Template1

peer default ipv6 pool test

ipv6 unnumbered Loopback0

ipv6 enable

ipv6 nd other-config-flag

no ipv6 nd ra suppress

ppp authentication chap

ipv6 dhcp server test

!

ipv6 local pool test 2001:DB8:12FF:FF::/56 64

!

ipv6 dhcp pool test

dns-server 2001:db8:1:1::1

!

[FlorianViaN]

Hello,

It works, thanks but why this loopback 2001:db8:12ff::1/128 ?

Can I configure mine ?

[Harold Ritter]

Hi Florian,

I am glad it is now working. The loopback IPv6 address was just and example. You can definitely change it to what ever address you want.

Regards

[FlorianViaN]

Hello,

I tried without the loopback and it works too, so is the loopback useful or not ?

It seems that the option no ipv6 nd ra suppress was the only missing command.

Regards

[Harold Ritter]

Hi Florian,

The loopback is used by the "ipv6 unnumbered" on the virtual-template1. You should configure it. It is usually a best practice to have a loopback interface configured on your router anyhow.

Regards

[FlorianViaN]

Thanks for all Harold.

Have a nice day, and maybe see you later with another question about IPv6.

Regards

[FlorianViaN]

Hello,

With a customer on PPP, I would like to have an access on the two website in VLAN 120.

I can ping the IPv6 but not the name, maybe the DNS doesn't work or something like this.

If you want any configurations, I am here.

Regards

[Harold Ritter]

Hi Florian,

Do you see the DNS address on the windows 7 workstation? Can you ping the DNS address? If so, try nslookup the web site host name.

Regards

[FlorianViaN]

Hello,

Yes, I see the DNS address and I can ping it.

However, nslookup the web site host name failed, DNS request time out.

So, may be, my DNS doesn't work correctly, I'm not sure (DNS = PowerDNS)

Thanks, regards.

[Harold Ritter]

Hi Florian,

Would there be an ACL in the path blocking access to port UDP 53 to your dns server?

Regards

[FlorianViaN]

Hello,

No ACL, I have the Firewall where I accepted all services.

Edit : When I put the network configuration manually on the PPP, it works...This is...surprising.

Regards.

[Harold Ritter]

Hi Florian,

Surprising indeed. What flavor of windows do you use?

Regards