cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

154
Views
0
Helpful
2
Replies
Beginner

DHCPv6 Relais Agent no auto static route for prefix delegation

Hello,

In order to deploy IPv6 on an infrastructure I realize different labs.

The objective of one of my labs is to set up a DHCPv6 relay on a cisco 2921 router to see how it reacts with the distribution of a prefix delegation.

In the documentation I read, the IPv6 DHCPv6 Relay Agent Notification feature is supposed to create a static route in the router's routing table when the router receives a DHCPv6 RELAY-REPLY. Here is the exact sentence:

 

"No user configuration is required for this feature. Static route management is done automatically by the relay agent."

 

However, on my lab no roads are automatically added. Here is my configuration:

Lab.png

Here is my configuration on R1:

interface GigabitEthernet0/0.950
 encapsulation dot1Q 950
 no ip proxy-arp
 ipv6 address FE80::950:2 link-local
 ipv6 address 2001:DB8:67:950::950:2/64
 ipv6 enable
 ipv6 nd managed-config-flag
 no ipv6 redirects
 ipv6 dhcp relay destination 2001:DB8:67:951::951:10
 ipv6 virtual-reassembly in
end
!
interface GigabitEthernet0/0.951
 encapsulation dot1Q 951
 no ip proxy-arp
 ipv6 address FE80::951:2 link-local
 ipv6 address 2001:DB8:67:951::951:2/64
 ipv6 virtual-reassembly in
end

The R2 router receives an IPv6 address on its WAN interface with a prefix delegation but no route to this prefix is created on R1.

Does anyone had an idea?

 

Best regards,

POM

Everyone's tags (2)
2 REPLIES 2
Highlighted
VIP Advocate

Re: DHCPv6 Relais Agent no auto static route for prefix delegation

Hi,

Please note that:

IPv6 routes are added when the relay agent relays a RELAY-REPLY packet, and IPv6 routes are deleted when the prefix delegation lease time expires or the relay agent receives a release message. An IPv6 static route in the routing table of the relay agent can be updated when the prefix delegation lease time is extended.

Regards,
Deepak Kumar,
Don't forget to vote and accept the solution If this comment will make help you!
Beginner

Re: DHCPv6 Relais Agent no auto static route for prefix delegation

Hi Deepak kumar,

 

I totaly agreed withs this fact. In my situation this is exactly what happens but no routes are added, the DHCPv6 server send a RELAY-REPLY to R1 (the relay agent) with the IPv6 prefix and R1 sends it to R2.

 

When I enable the ipv6 dhcp debug on R1, I see RELAY-REPLY messages passing by. So I don't understand why no roads are added.

 

Regards,

POM

CreatePlease to create content
Content for Community-Ad
August's Community Spotlight Awards


This widget could not be displayed.