Not that simple. By making a node listen on both IPv4 and IPv6, they
will accept connections from both, but other nodes will still only
trying to connect to this node on the address it is broadcasting. That
means if a node's broadcasting a IPv4 address, then all other nodes in
the cluster must be able to reach it on that IPv4 address. That's why
you'll need NAT64 to make sure the IPv6-only nodes can reach the
dual-stack nodes on their IPv4 addresses.
On 18/11/2022 09:12, Lapo Luchini wrote:
So basically listen_address=:: (which should accept both IPv4 and
IPv6) is fine, as long as broadcast_address reports the same single
IPv4 address that the node always reported previously?
The presence of broadcast_address removes the "different nodes in the
cluster pick different addresses for you" case?
On 2022-11-16 14:03, Bowen Song via user wrote:
I would expect that you'll need NAT64 in order to have a cluster with
mixed nodes between IPv6-only servers and dual-stack servers that's
broadcasting their IPv4 addresses. Once all IPv4-broadcasting
dual-stack nodes are replaced with nodes either IPv6-only or
dual-stack but broadcasting IPv6 instead, the NAT64 can be removed.
On 09/11/2022 17:27, Lapo Luchini wrote:
I have a (3.11) cluster running on IPv4 addresses on a set of
dual-stack servers; I'd like to add a new IPv6-only server to the
cluster… is it possible to have the dual-stack ones answer on IPv6
addresses as well (while keeping the single IPv4 address as
broadcast_address, I guess)?
This sentence in cassandra.yaml suggests it's impossible:
Setting listen_address to 0.0.0.0 is always wrong.
FAQ #1 also confirms that (is this true also with broadcast_address?):
if different nodes in the cluster pick different addresses for you,
Bad Things happen.
Is it possible to do this, or is my only chance to shutdown the
entire cluster and launch it again as IPv6-only?
(IPv6 is available on each and every host)
And even in that case, is it possible for a cluster to go down from
a set of IPv4 address and be recovered on a parallel set of IPv6
addresses? (I guess gossip does not expect that)
thanks in advance for any suggestion,
