Chapter 16. Using NetworkManager to disable IPv6 for a specific connection

Procedure

1. Optional: Display the list of network connections:

   # nmcli connection show
   NAME    UUID                                  TYPE      DEVICE
   Example 7a7e0151-9c18-4e6f-89ee-65bb2d64d365  ethernet  enp1s0
   ...

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2. Set the ipv6.method parameter of the connection to disabled:

   # nmcli connection modify Example ipv6.method "disabled"

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3. Restart the network connection:

   # nmcli connection up Example

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Verification

1. Display the IP settings of the device:

   # ip address show enp1s0
   2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
       link/ether 52:54:00:6b:74:be brd ff:ff:ff:ff:ff:ff
       inet 192.0.2.1/24 brd 192.10.2.255 scope global noprefixroute enp1s0
          valid_lft forever preferred_lft forever

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   If no inet6 entry is displayed, IPv6 is disabled on the device.

2. Verify that the /proc/sys/net/ipv6/conf/enp1s0/disable_ipv6 file now contains the value 1:

   # cat /proc/sys/net/ipv6/conf/enp1s0/disable_ipv6
   1

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   The value 1 means that IPv6 is disabled for the device.