Unique IP address across the cluster

[subrnath]

We are invoking IPVLAN plugin via multus-cni. Each POD is allocated an unique IP address from the subnet start and end range ( as mentioned in IPAM args). But the uniqueness of the IP is in a host and not across the cluster. /var/lib/cni/networks/<network_id>/last_reserved_ip.0 maintains the last allocated ip for the subnet/network and it's maintained in each host.

It will be good, if multus-cni provides the uniqueness of the IP address across the cluster level.

[s1061123]

Hi @subrnath

Regarding above comment, you may use 'host-local' plugin for IP Address Management (IPAM) and the issue is related to 'host-local' plugin, not multus-cni.
https://github.com/containernetworking/plugins/tree/master/plugins/ipam/host-local

Multus-cni just invokes CNI plugin (including IPAM) as a meta plugin, so I guess it might be wrong place to discuss about it.
Could you please double check about it?

[subrnath]

Thanks. Yes, we are using host-local. So with what is the IPAM option to have cluster wise unique IP address? So as i understand, host-local ensures host wise unique IP address.

[s1061123]

@subrnath This is out-of-topic of multus, but how about dhcp CNI IPAM plugin?
Or you can use other overlay CNI plugins which also provides cluster wise unique IP address in overlay network.

That's what I know. Can I close the issue?

[s1061123]

@subrnath just a reminder.

I will close it in someday next week.

[subrnath]

We can't use dhcp CNI IPAM plugin because POD IP to be assigned to the POD needs to be known before the deployment is made so that same IP is fed in the bootstrap service.

Agree we can close the thread.