IPv6 RA DNS support on Catalyst 3560/3750 platforms?

[andrew.butterworth]

I am playing around with Android and IPv6 on a wireless network.  I have a WLC connected to a Catalyst 3560G L3 switch running the latest IOS (IP Services 15.0(2)SE11).  IPv6 is working fine and I am using Stateless address assignment with DHCP to provide the 'other' options including DNS servers.  Configuration on the various SVIs is like this:

ipv6 address My-Prefix-48 ::64FE:0:0:0:FE/64
ipv6 enable
ipv6 nd other-config-flag
no ipv6 redirects
ipv6 dhcp relay destination 2001:0:0:0:192:168:1:1

The DHCPv6 server is Windows 2012R2 and doesn't have any IPv6 scopes, just some global server options for DNS.  This works perfectly for my Windows 7+ machines.  Most implementations of Android however don't have a DHCPv6 client included and adding one requires root etc so not an option really.  Android however does support (R)DNS.  Unfortunately this isn't available on the 3560/3750 platform.  I have checked on a 3650 running 16.8.1a and it is available here, as well as a C891F router running 15.6.1.

I know the 3560/3750 platform is EoL but is there any possibility that this will be added or am I just daydreaming?

Andy

[Seb Rupik]

Hi Andy,

As you point out, both platforms are in their EoL phases in fact both have sailed past the 'last date of support' marks, crucially the last software maintenance date was 4 years ago.

You will not see RA DNS support on these platforms. Time to upgrade or move the function to an existing platform which does.

cheers,

Seb.

[andrew.butterworth]

I thought as much TBH.  The problem is there is nothing new in the later switches that will force many customers to upgrade.  A working 48 port 1Gbps switch to a new 48 port 1Gbps switch - why upgrade?  If it breaks, then there is a reason to upgrade but other than that what are the drivers?

MACSEC, TrustSEC - I have seen one customer testing it, but no real deployments of it.  Even 802.1x - I have a few customers who have it deployed, but not many - plus I can do that on a 3560 though (I can even do it on a 2950....).  IPv6 - its starting to appear on more customer LANs, but again its been in 3560/3750 code for ages (RDNS aside...).

Looks like its a re-engineer piece of work to get the WLC connected to a newer platform.  Wired clients though are staying on the 3560/3750s that are out there.

[Seb Rupik]

Agreed, but how would cisco put food on its table if users just held onto their hardware until it burnt out. Obsolescence is achieved through lack feature support and an ever growing list of security vulnerabilities! That is the reality of proprietary IT.

Anyhow...years ago when IPv6 support was very limited on cisco kit we used the radvd service on linux to provide our RA broadcasts. I see it now supports RDNS. To get this working you'd need to configure a sub-interface on every VLAN in your network and confirm with infosec that you cannot route between them.

https://linux.die.net/man/8/radvd

cheers,

Seb.