Why do the connected devices to the router have the smae IPV6 address?

[xmg1860ming]

Hi,

Now I meet the issue

The operation steps on router (WRVS4400N):

1.Set the IP mode as Dual-stack IP and then save

2.Disable the IPV4 DHCP server

3.Use other deivces to connect the router.

The connected devices have the same IP address(2005:123:456:789::1),I am confused,why is it?

please help.

Thanks!

[jeffrrod]

Dear Ming,

Thank you for reaching Cisco Small Business Support Community.

I suggest you to get in contact with the Small Bussiness Support Center in order to address your inquiry;

https://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

Kind regards,

Jeffrey Rodriguez S. .:|:.:|:.
Cisco Customer Support Engineer

*Please rate the Post so other will know when an answer has been found.

[jonatrod]

Hi Ming, to add to Jeffrey´s post, an IP address serve the purpose of uniquely identifying an individual network interface of a host, locating it on the network, and thus permitting the routing of IP packets between hosts. For routing, IP addresses are present in fields of the packet header where they indicate source and destination of the packet.

One of the advantages of IPv6 is the fact that every link has a link  local addresses that are significant only for that link, in addition to  having at least one global address.  The fact that the same link-local  address can appear on multiple different links should be embraced as a  benefit.

I will share some configuration documents in order to help you if you have any problem with your settings, you can see the information here, you can also take a look to the administration guide on section 5.

"I hope you find this information useful Ming"

Greetings, 
Johnnatan Rodriguez Miranda.
Cisco Network Support Engineer.

[almoncad]

Hello,

The WRVS4400N is in fact assigning IPv6 addresses to all the devices connected to it, but the WRVS4400N does not show a table with the IPv6 addresses assigned to each device connected, it only shows the IPv4 addresses and the respective MAC address for each device. The IPv6 of the WRVS4400N is an aggregetable global unicast IPv6  address (See the image below)

If you go to Setup > LAN you will see that you cannot modify the prefix of the IPv6 address, all you can modify is the postifx and prefix length field (As you can see in the image below).

For more information about these fields and general IPv6 configuration,  please refer to the article IPv6 Configuration on WRVS4400N Wireless-N  Gigabit Security Routers

The only way you have to see the IPv6 address assigned to each device connected to the WRVS4400N is to check on each device the IPv6 address assigned. The WRVS4400N does not provide this information. You can see from the below picture the IPv6 address assigned to my computer. As you can see, the WRVS4400N assign the the computer the prefix 2002:c0a8::/6. Then you can see the actual IPv6 address which is 2002:c0a8:0:b182:e6a:9b0e:cdcf.

As you can see, the initial part (The prefix) remains the same, since these are the first 64 bits of the whole IPv6 address. The other 64 bits of the IPv6 address represents the interface ID, that is, the device that is connected to the WRVS4400N.

I hope you find this information helpful. If you have further questions, don't hesitate to ask.

Alejandro Moncada
SBCD Engineer
almoncad@cisco.com

[xmg1860ming]

Dear,

I updated the rounter version "WRVS4400Nv2_v2.0.2.1", and then use other phones connect the rounter ,the phones still display same IPV6 address,

our engineer think the issue is caused by router ,the router assign the wrong frame.the data packet does be IPV6 type,but the frame header is marked wrongly as IPV4 type.

so please help to check. attched the logs. thanks!