IPv6 configuration of RV260

[familieboehler]

Hi dear experts,

I am having problems to configure and a lack of understanding the technique.

My setup: ISP via DOCSIS to modem (in bridge mode) to the RV260 router. Behind the RV260 are a Catalyst 9115 and several Clients connected by LAN (1GB copper). The ISP claims to deliver native IPv6.

In WAN-Settings I have activated for IPv6 DHCP, Use DHCP Provided DNS Server and DHCP-PD activated. As far I understood the Prefix Name it is anything as desired alphanumerical and set by me to "ISP".

In the System Summary I can see

This brings me to my first question: Is it correct that there is no DNS shown?

To get IPv6 running for the clients I have configured the LAN, VLAN1 as follows:

Unfortunately this does not work for all clients. The laptop (Linux, Ubuntu 22.04) reports as connectivity IPv4 and a whole bunch of IPv6 addresses and is able to connect to IPv6 websites (e.g. ipv6.google.com). The http://test-ipv6.alpinedc.ch/ successfully reports IPv6 connectivity. This is both on LAN and on WLAN connections. A Samsung S22 reports an IPv4 and one IPv6 (FE80::xx) address. All tests towards IPv6 fail. Why?

PD Selection as above and Range Start/End are connected. The PD is coming from where? The ISP delivers dynamic IPv6 only. So will this change? And what happens to the range then?

And I am not really satisfied. I would like to set up a second VLAN but there pops up the message that the VLAN's are within the same range. How to solve this?

Using

Prefix from DHCP-PD instead gives fe80::xx addresses to all clients only and no connectivity to IPv6 WWW at all. Am I missing a setting anywhere else?

What is the suffix? What influence does it have? Which systematic would follow the correct entry?

DNS Server: using DNS provided by ISP does not work. Is there on the RV260 any possibility to find out if the ISP delivers the desired information?

And the last point: Activation of IPv6 in the WAN section presents me <error>dnsmasq: failed to allocate -1 bytes - depending to the WAN IPv6 setting between several times a minute (DHCP, SLAAC) to about once every second hours (Static). My assumption is that I am missing a setting somewhere - but so far I could not figure out the place to look at.

I am stuck here - even presumably the questions are pretty basic.

Please assist.

Kind regards

[Harold Ritter]

Hi @familieboehler ,

> This brings me to my first question: Is it correct that there is no DNS shown?

This probably just means your provider doesn't provide an ipv6 dns address via dhcpv6, but you should still be able to use the ipv4 DNS address.

> A Samsung S22 reports an IPv4 and one IPv6 (FE80::xx) address. All tests towards IPv6 fail. Why?

FE80:: is the link local address and is only used for communication between devices on the same link. Your Samsung device does not get a global unicast address (GUA) ipv6 address, that would allow it to access the ipv6 Internet, because Android still does not support dhcpv6. You would need to use SLAAC instead of dhcpv6 on the lan side. I believe this would be done by disabling the DHCP server in the vlan configuration.

> I would like to set up a second VLAN but there pops up the message that the VLAN's are within the > same range. How to solve this?

You need to configure a different suffix for each vlan. The suffix value will be appended to the /56 received from dhcpv6 PD to create a unique /64 for each vlan. You can assign 0:0:0:0:0 for the first clan and 1:0:0:0:0 for the second vlan and so on.

Regards,

[familieboehler]

Hi Harold, thank you for your feedback - It gives new thoughts and hints toward target specific tests to me. As soon I have clear results I will come back.

[familieboehler]

Hi Harold,

Switching off the DHCP Server within VLAN IPv6 and setting the router advertisement to SLAAC (RA Flags "Managed" and "Other" deactivated) gives no IPv6 connectivity at all. The devices have a fe80 address and that's it.

Back to IPv6 DHCP on VLAN1: using the DHCP-PD from the ISP gives a Prefix 1:2:3::/56. I add the Suffix 4::. The preview shows with prefix length 56 1:2:3:4::, with prefix length 64 1:2:3::. Using either prefix lenght on VLAN1 and VLAN2 simultaneously gives the error "Same subnet is been used!". Using /56  other one and /64 on the first view everything looks fine. But in the Router advertisement for both 1:2:3:: is showed, once with /56 and once with /64. For me this seems the same? I do not understand this behavior. Could anyone explain to me please?

Kind regards

[Harold Ritter]

Hi @familieboehler ,

> Switching off the DHCP Server within VLAN IPv6 and setting the router advertisement to SLAAC     >(RA Flags "Managed" and "Other" deactivated) gives no IPv6 connectivity at all. The devices have a > fe80 address and that's it.

There has to be something wrong with the RA. Can you please provide the output for the router advertisement configuration screen.

> Back to IPv6 DHCP on VLAN1: using the DHCP-PD from the ISP gives a Prefix 1:2:3::/56. I add the > Suffix 4::.

Try setting the prefix length to 64 and the suffix to 1:0:0:0:1 for vlan1 and 2:0:0:0:1 for vlan2 and provide the results of the preview for each vlan.

> Using /56  other one and /64 on the first view everything looks fine.

The prefix needs to be a /64. SLAAC will not work otherwise. 

You should definitely focus on getting SLAAC working, as it is the only method that will work for both the workstations and the Android devices.

Regards,

[familieboehler]

Hi Harold,

Thank you for your help!

Setting the Prefix Lenght to /64 crops the the first block of the suffix?

That's the entry

and that is it how it looks after "Apply"

Do you have a clue to that?

Kind regards

[Harold Ritter]

Hi @familieboehler ,

I am not too sure what is the suffix value expected by the RV260 and I have not found helpful configuration example.

I am not sure either why the prefix included in the RA is a /56. This is the reason why the hosts can't auto configure themselves.

There has to be a way to set the 8 bits between /56 and /64 or maybe not.

What version are you running by the way?

Regards,

[familieboehler]

Hi Harold,

Just putting the 1 fills the Preview from the end, regardless of prefix lenght

Might there be another menu hidden somewhere else to fill in these 8 bits? What might be the title?

Version is RV260P-K9 V04 Firmware Version 1.0.01.10

Kind regards

[Harold Ritter]

Hi @familieboehler ,

You are running the current FW version.

The question I have is if that feature is properly supported. Do you have a support contract so you could open a case? I would definitely recommend you to do so.

Meanwhile I will try to reach out to our team internally to see what I can find. I will get back to you if I can get any additional information.

Regards,

[familieboehler]

Hi Harold,

thank you for this clear statement.

I am not aware of any subscription for my private Cisco-Products ...

Kind regards

[familieboehler]

Hi Harold,

I have rebooted the router to factory default (including certificates) and configured the whole thing new.

There has nothing changed in the behavior of IPv6 sufffixes. Unfortunately.

[familieboehler]

Hi together,

I've undergone further testing and variants of configurations, checking accessibility of IPv6-sites and warning- and error messages in the logs of the RV260.

My mindset goes meanwhile the direction that the router firmware is pretty much buggy in all means concerning IPv6. 

Unfortunately this thing is only 3 years old and should have had to live another couple of years.

What are the experience with ISR 1111? Better?

Would appreciate any hint

Regards

[familieboehler]

Found CSCwc50260 but unfortunately can't access the entire content. Seems to be related to the described problems and seems to be in the known issue section.