Are you aware that 80 on the end of dhcp-range is lease time, not any prefix size? Consider using of constructor:tapvm4qyj3a instead of manual end address. If I see correctly the end address is the same as the start address. Not sure how this should behave, but I would not be surprised if it did not work.

Try this:

dhcp-range=2a01:4f9:2b:35a:7df2::2,constructor:tapvm4qyj3a,80

On 18. 04. 23 10:40, Daniel Farina wrote:
Hello everyone,

I have been trying to set up an IPv6-only network for a virtual machine with route advertisements and DHCP configuration. I've had some success, but I have a question.

I have a dnsmasq.conf that looks like this, to delegate a /80 chunk of a /64 network to a virtual machine:

interface=tapvm4qyj3a
enable-ra
dhcp-authoritative
leasefile-ro
ra-param=tapvm4qyj3a,mtu:1280,high,60,1200
dhcp-range=2a01:4f9:2b:35a:7df2::2,2a01:4f9:2b:35a:7df2::2,80

If I have an address configuration like this on the host outside the virtual machine, it works well:

3: tapvm4qyj3a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 82:d6:93:69:72:82 brd ff:ff:ff:ff:ff:ff
    inet6 2a01:4f9:2b:35a:7df2::1/80 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::80d6:93ff:fe69:7282/64 scope link
       valid_lft forever preferred_lft forever

The thing I find dissatisfying about this is that the VM is not able to listen on 2a01:4f9:2b:35a:7df2::1 anymore once I've done this, is my understanding: the host will process the traffic, right? If I remove the address on the guest's network, dnsmasq warns me repeatedly, and does not work:

ip addr del 2a01:4f9:2b:35a:7df2::1/80  dev tapvm4qyj3a

dnsmasq-dhcp: no address range available for DHCPv6 request via tapvm4qyj3a dnsmasq-dhcp: no address range available for DHCPv6 request via tapvm4qyj3a dnsmasq-dhcp: no address range available for DHCPv6 request via tapvm4qyj3a
...

My question is partially that of norms: is it normal to squat on a bit of the guest's address space like this? Is there a preferred way that avoids this, or does something different still? I know that a number of non-SLAAC configurations tend to sit on ::2 as the first unicast address, is this related to the reason why?

I will be expanding my use of dnsmasq to DNS, so this may figure in the answer.

Thank you for considering my question.

_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss

--
Petr Menšík
Software Engineer, RHEL
Red Hat, http://www.redhat.com/
PGP: DFCF908DB7C87E8E529925BC4931CA5B6C9FC5CB


_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss

Reply via email to