CentOS 6 - DHCPv6

odbod · 06-27-2014, 03:39 PM

Alright, so I'm having a bit of trouble here on my CentOS 6 router. I have radvd running for router advertisements and I have dhcpd6 running to provide my hosts with specific IP's that I want to give them. Below are my configurations.

This is my /etc/radvd.conf

Code:

interface vi0 {
        AdvLinkMTU 1500;
        AdvSendAdvert on;
        AdvManagedFlag off;
        AdvOtherConfigFlag on;
        MinRtrAdvInterval 3;
        MaxRtrAdvInterval 10;
        prefix 2001:470:d:286::/64 {
                AdvOnLink on;
                AdvRouterAddr on;
                AdvAutonomous off; };
};

This is a portion of /etc/dhcp/dhcpd6.conf.

Code:

#
# DHCP for IPv6 Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd6.conf.sample
#   see 'man 5 dhcpd.conf'
#   run 'service dhcpd6 start' or 'dhcpd -6 -cf /etc/dhcp/dhcpd6.conf'
#

# Logging
log-facility local7;

# Global Defaults
allow leasequery;
authoritative;
default-lease-time 2592000;
preferred-lifetime 604800;
option dhcp-renewal-time 3600;
option dhcp-rebinding-time 7200;
option dhcp6.info-refresh-time 21600;
#max-lease-time 7200;

subnet6 2001:470:d:286::/64 {
        interface vi0;
        range6 2001:470:d:286::1100 2001:470:d:286::1254;
        option dhcp6.name-servers 2001:470:d:286::1,2001:4860:4860::8888,2001:4860:4860::8844;
        option dhcp6.domain-search "bromosapien.net";
}

# My Devices
host sokel {
        host-identifier option dhcp6.client-id 00:01:00:01:1A:D1:F0:78:00:00:00:00:00:00;
        fixed-address6 2001:470:d:286::2;
}

The problem is, the clients on the network are not getting IP's. They are getting the DNS information perfectly fine, but they do not get IP's from the range I specified, nor is my 'host' block here even working.

If I change AdvAutonomous, IP's will start coming out, but, if they are already configured with a static address, they get another address. Or, if they're the host "sokel", they get both the ::2 address and another IPv6 address that is WAY outside of the range I specified.

What is the preferred way to make this 'stateful' and make it so the clients will pull IP's from the range I specify or get an address I specify in a host block? What am I doing wrong exactly for what I want to achieve?

Summary of what I'm trying to achieve:

Clients not in host blocks get an IP in the range specified in the subnet block
Each host only gets one address, including the ones in the host blocks or statically configured hosts

** Update **

If DHCPv6 is on by itself, with no radvd, IP's are handed out as needed. If radvd turns on (with the configuration above), they all lose their addresses. Not sure how to prevent that.

halvy · 06-29-2014, 03:12 PM

Did you get it sorted?

I'm afraid I will prol not be much help..

I have used isc-dhcp only (or dhcp6)... I know you MUST have a static addy to get it to give it's new issued one.

Have you tried starting the radvd FIRST-- then the dhcp?

Halvy

odbod · 06-29-2014, 07:38 PM

I did not yet. Still working on it.

Yes, I have tried starting radvd first and then firing up dhcpd6 afterward. Addresses do not get handed out either way. If I do start dhcpd6 first, everyone gets their address. Starting radvd after, any new clients do not get addresses. Kind of a drag.

halvy · 06-29-2014, 07:54 PM

I guess you covered all the basic stuff correctly, like setting up the subnets (for the new clients).

When you say new clients.. you mean those that try to connect, after you first turn everyone on (at initial startup/reboot)?

I really lack in router skills, other than my local inet simple setup.

- I would think only ONE of your servers (dhcp prol) should be the ONLY one concerned with handing out addys.. no? Forgive me if I sound stupid.

-- I know you mentioned you are trying to do more than one thing.. so I suppose a second server (the router?) is needed to ALSO hand out numbers?

- If you do indeed need BOTH.. is it possible that the 4/6 protocols are conflicting..or where the problem might be happening?

- Are you testing this properly... from a real life angle? Ie. from outside your subnets and hosts?

I'm not sure any of this even makes sense what I am asking you.. and I hope I am not wasting your time. I am just suggesting.. what I would do.

Plus, I am interested in your outcome, since I will be dealing with stuff like this (very soon)... so whenever I find an issue that is over my head, but interesting, I try to either help or watch it's progress =:]

Halvy

odbod · 06-29-2014, 08:12 PM

I only have one server that handles the DHCP/NAT/firewall of the entire network. Everyone gets their connection to the internet through here. This server has an IPv6 tunnel to it, and I have a KVM machine in the back that has statically configured IPv6 addresses, so those work for obvious reasons. The new clients that connect to the network, do not get their addresses if radvd and dhcpd6 are both running with my configurations in my original post. DHCPD6 works though by itself, with radvd off.

Not sure if there would be a conflict per say.