[Dnsmasq-discuss] Can Dnsmasq be told not to advertise a specific prefix via RA?

[Christopher Martin]

Greetings,

Is it possible to prevent Dnsmasq from advertising a specific prefix via
router advertisements?

Here's my situation. My ISP provides a dynamic IPv6 prefix which, using
wide-dhcpv6, ends up assigned to interface bond0. Dnsmasq then advertises
the prefix on bond0 out to the LAN. The various hosts on the LAN use it,
together with IPv6 privacy extensions, to generate global IPv6 addresses.
So far so good.

For reference, my config is as follows:

dhcp-range=::,constructor:bond0,ra-only,infinite

Here's the problem. I also assign a ULA to bond0 (fd00:etc.). Dnsmasq also
advertises this prefix to the LAN, but I don't want it to, because then the
other hosts on the LAN end up generating addresses based on it, including
via IPv6 privacy extensions. Whereas what I want is to manually assign each
host its own specific, unchanging and easily remembered ULA, which should
also be the source IP used when connecting to various services around the
LAN. Too many ULAs cause problems.

Is there a way to instruct Dnsmasq to _not_ advertise the ULA prefix, but
to continue advertising the global prefix from my ISP? Perhaps this option
already exists and I've simply missed it - apologies if that's the case.

Thanks very much,

Christopher Martin

[Simon Kelley]

Can you also add a dhcp-range for the ULA range, which deprecates it?

Cheers,

Simon.

Post by Christopher Martin
Greetings,
Is it possible to prevent Dnsmasq from advertising a specific prefix via
router advertisements?
Here's my situation. My ISP provides a dynamic IPv6 prefix which, using
wide-dhcpv6, ends up assigned to interface bond0. Dnsmasq then
advertises the prefix on bond0 out to the LAN. The various hosts on the
LAN use it, together with IPv6 privacy extensions, to generate global
IPv6 addresses. So far so good.
dhcp-range=::,constructor:bond0,ra-only,infinite
Here's the problem. I also assign a ULA to bond0 (fd00:etc.). Dnsmasq
also advertises this prefix to the LAN, but I don't want it to, because
then the other hosts on the LAN end up generating addresses based on it,
including via IPv6 privacy extensions. Whereas what I want is to
manually assign each host its own specific, unchanging and easily
remembered ULA, which should also be the source IP used when connecting
to various services around the LAN. Too many ULAs cause problems.
Is there a way to instruct Dnsmasq to _not_ advertise the ULA prefix,
but to continue advertising the global prefix from my ISP? Perhaps this
option already exists and I've simply missed it - apologies if that's
the case.
Thanks very much,
Christopher Martin
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Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss

[Christopher Martin]

Thanks for the suggestion. That does work, although it's a bit messy to
have to advertise a prefix you don't want the clients to use.

Cheers,
Christopher Martin

Post by Simon Kelley
Can you also add a dhcp-range for the ULA range, which deprecates it?
Cheers,
Simon.

Post by Christopher Martin
Greetings,
Is it possible to prevent Dnsmasq from advertising a specific prefix via
router advertisements?
Here's my situation. My ISP provides a dynamic IPv6 prefix which, using
wide-dhcpv6, ends up assigned to interface bond0. Dnsmasq then
advertises the prefix on bond0 out to the LAN. The various hosts on the
LAN use it, together with IPv6 privacy extensions, to generate global
IPv6 addresses. So far so good.
dhcp-range=::,constructor:bond0,ra-only,infinite
Here's the problem. I also assign a ULA to bond0 (fd00:etc.). Dnsmasq
also advertises this prefix to the LAN, but I don't want it to, because
then the other hosts on the LAN end up generating addresses based on it,
including via IPv6 privacy extensions. Whereas what I want is to
manually assign each host its own specific, unchanging and easily
remembered ULA, which should also be the source IP used when connecting
to various services around the LAN. Too many ULAs cause problems.
Is there a way to instruct Dnsmasq to _not_ advertise the ULA prefix,
but to continue advertising the global prefix from my ISP? Perhaps this
option already exists and I've simply missed it - apologies if that's
the case.
Thanks very much,
Christopher Martin
_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss

_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss