[Dnsmasq-discuss] dnsmasq 2.78 is failing to respond to dhcpv6 requests forwarded via relay agent

[Geert Stappers]

On Fri, Jan 04, 2019 at 05:34:03PM +0530, Sandeep K M wrote:
> Hi,
> 
> On Fri, Jan 4, 2019 at 3:59 PM Geert Stappers wrote:
> > On Fri, Jan 04, 2019 at 02:47:11PM +0530, Sandeep K M wrote:
> > > On Fri, Jan 4, 2019 at 2:30 PM Geert Stappers wrote:
> > > > On Fri, Jan 04, 2019 at 11:55:49AM +0530, Sandeep K M wrote:
> > > > > [ .... ]
> > > > > Please let me know if any other information is required.
> > > >
> > > > At the server
> > > >   ip link       # what interfaces are there
> > > >   ip -6 address
> > > >   ip -6 route
> > >
> > > Here are the output of the commands:
> > >
> > > root at 8320:~# *ip -6 addr*
> > > 49: m1s1p7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UNKNOWN qlen 1000
> > >     inet6 1040::2/120 scope global
> > >        valid_lft forever preferred_lft forever
> > >     inet6 fe80::480f:cf00:7af:8444/64 scope link
> > >        valid_lft forever preferred_lft forever
> >
> > Based upon that: there is only 1 interface

But it are about sixty


> > > root at 8320:~# *ip -6 route*
> > > 1040::/120 dev m1s1p7  proto kernel  metric 256  pref medium
> > > 2020::/120 via 1040::1 dev m1s1p7  proto static  metric 512  pref medium
> >
> > So there is some kind of routing information where the 2020::/120 network
> > is ...
> >

In the non-stripped version
> fe80::/64 dev bridge-vrf  proto kernel  metric 256  pref medium
> fe80::/64 dev tap0  proto kernel  metric 256  pref medium
> fe80::/64 dev tap-br0  proto kernel  metric 256  pref medium
> fe80::/64 dev m1s1p7  proto kernel  metric 256  pref medium
(do notice there is no default route)

> > > Sorry forgot to capture "ip link" output. The setup is disassembled as of
> > > now but if it is required then I will recreate the setup and send you the
> > > output.
> >
> > Come again?
> > As in: "How was the output of `ip -6 addr` and `ip -6 route` generated?"
> >
> These command output is what I have captured previously for my reference
> before dissembling the setup.

OK. Thanks for explaining.

> *I have recreated the setup and attached (ip-command-output.txt) is the
> output of the commands that you have requested in full*.

> Please let me know if any other information is needed.

Not yet mentioned in this thread is working connectity between "server"
and "client".  This will require temporary manual configuration
of an IPv6 address at client. Let say it is 2020::2/120.
Then verify with more than "ping". Example given:  `ssh 1040::2`

It shall reveal how well router ( with the odd name 'Switch' ) is
configured for routing between 1040::/120 and 2020::/120.
Also if the ssh deamon is able to send packets out on the right
interface.

I do know that it might seem a detour. And we also known that
original poster is already stuck with current setup. So the "detour"
could be a step forward.   Good luck.


Groeten
Geert Stappers