dhcpcd-discuss

Hi

Firstly, sorry about the delay - I've been knee deep in working on 
dhcpcd-9. It's now in a state I can look into addressing a few other things.

On 05/12/2019 12:27, Shweta Kalyani wrote:
> Hi Roy,
>
> We are using DHCPCD version 7.2.3.

For reference, I've tested dhcpcd-7.2.3, dhcpcd-8.1.2 and the latest 
dhcpcd-9 code against wide dhcp6s.

> The CDRouter reported a PD renumbering test case failure for IA_PD.
> Below is a description of the same:
>
>      step 1. Change the client's DHCPv6 binding to use the new IPv6
>              prefix specified by the testvar "dhcpv6WanAssignNextPrefix"
>      step 2. Verify DHCPv6 client sends DHCPv6 Renew or Request
>      step 3. Verify Renew or Request contains IA_PD option (26) for
>              same prefix
>      step 4. Send valid DHCPv6 Reply with new prefix
>      step 5. Verify client updates router advertisements on LAN with new
>              prefix information
>      step 6. Send pings from LAN client to an IPv6 remote host on the
>              WAN to verify connectivity with new prefix
>      step 7. Restore client's original prefix by repeating Steps 1
>              through 5 using original IPv6 prefix
>      step 8. Send pings from LAN client to an IPv6 remote host on the
>              WAN to verify connectivity with original prefix
>
>      Reference: IETF RFC 3633 Section 12.1 "Requesting router behavior"
>
>      Upon the receipt of a valid Reply message, for each IA_PD the
>      requesting router assigns a subnet from each of the delegated
>      prefixes to each of the links to which the associated interfaces are
>      attached, with the following exception: the requesting router MUST
>      NOT assign any delegated prefixes or subnets from the delegated
>      prefix(es) to the link through which it received the DHCP message
>      from the delegating router.
>
> The issue lies at step 5. The dhcpcd client fires a DELEGATED6 event but 
> the $new_delegated_dhcp6_prefix is missing due to which the DUT is 
> unable to update RA on LAN with new prefix.
> Please find attached dhcpcd-hook.log (has dhcpcd environment variable 
> info), dhcpcd.log and wan captures.
>
> Would really appreciate your help on this.

I cannot replicate your issue at all - in all cases renumbering the 
prefix delegation still has the address in both the DELEGATED6 
environment and added the downstream interface.
I can also see that when it fails

The big difference though is that your reply has two prefix delegations 
whereas wide dhcp6s can only send the one. The first (old) delegation 
has zero lifetime and this also could be something too look at.

I am currently unable to test using ISC dhcpd because it segfaults on my 
router (also unsure how to set it up for prefix delegation). I'll try 
and resolve this first - might take a while as compiling on an ERLITE is 
dog slow and I don't want to update the NetBSD on it right now for other 
reasons.

If I sent patches, can you test them against dhcpcd-8.1.2 or are you 
dead set on using dhcpcd-7.2.3? I ask because I don't actively support 
dhcpcd-7 aside from security issues ...... but this is a very 
interesting issue to solve regardless.

Roy