Folatt:

My modem is automatically entering the wrong ipv6 address for my main computer, resulting into odd behaviour like not being able to ping my server computers. The address it enters is 73a:34a1:5d16:a67f when it should be 5766:a840:f358:5b00.

• Setup

  • Desktop computer (MyComputer)
    • ASRock
      • Arch Linux
  • Modem
    • Fritz!Box 7581

IP lookup

[me@MyComputer ~]$ ip -6 addr
1: lo:  mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp5s0:  mtu 1500 state UP qlen 1000
    inet6 2001:983:8610:1:5766:a840:f358:5b00/64 scope global dynamic noprefixroute 
       valid_lft 6571sec preferred_lft 3492sec
    inet6 fe80::90d9:53e6:a878:801c/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

/etc/dhcpcd.conf

# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.

# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
# Some non-RFC compliant DHCP servers do not reply with this set.
# In this case, comment out duid and enable clientid above.
duid

# Persist interface configuration when dhcpcd exits.
persistent

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Most distributions have NTP support.
option ntp_servers
# Respect the network MTU. This is applied to DHCP routes.
option interface_mtu

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac private
noipv4ll