Docker container is assigned two Ipv6 addresses


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Hi all, 

 

I just noticed a weird behaviour while migrating some docker containers to Ipv6. They appear to be assigned two different ipv6 addresses on the same subnet. Ip addr on a container

 

eth0@if108: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:28:04 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.40.4/24 brd 192.168.40.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2a01:****:****:**e4:****:****:****:2804/64 scope global dynamic mngtmpaddr 
       valid_lft 86392sec preferred_lft 14392sec
    inet6 2a01:****:****:**e4::7/64 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::42:c0ff:fea8:2804/64 scope link 
       valid_lft forever preferred_lft forever

 

The 2a01:****:****:**e4::/64 subnet is configured on VLAN 40 with Router Advertisement on a pfsense VM. In Unraid > Settings > Network settings, VLAN 40 is configured with IPV4 and IPV6, and but no ip are assigned (because I don't want to access my server on this subnet, only web services, docker and VMs). 

 

Finally, containers are using the br0.40 interface and here is the configuration in Settings > Docker for ipv6

IPv6 custom network on interface br0.40:
Subnet: 2a01:****:****:**e4::/64 Gateway: 2a01:****:****:**e4::1 DHCP pool: not set

One last thing, when disabling Router Advertisement on this interface in pfSense, the stateless ip is no longer generated. Only remains 2a01:****:****:**e4::7. Why is this last ip assigned whereas there is no DHCP pool nor RA ? 

Could it be related to this bug report ?

 

Thanks everyone 

Edited by potjoe
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  • 1 year later...

Similar issue here,

I deploy a qbittorrent with static IPv6 [fc00::1004].

unraid.thumb.png.a02dc41bb12157788c833eb5d3e93009.png

 

 

However, it will always automatically assign an additional IPv6 (related to MAC address).

qb.png.d89db7b69335abac96f524a0fa2b4102.png

 

portainer.thumb.png.e59dc561b230f48800d9997e3b0738c1.png

 

By checking my router's connection, these two ips are both active.

 connection.png.4d9930563506b9c870025b10a51b3c1b.png

 

my question is, how to disable one of these two ips

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