# Creation of dummy ipv6 IP address during kickstart **URL:** \ **Category:** Rocky Linux Help & Support\ **Created:** [January 7, 2022, 12:55pm UTC](https://forums.rockylinux.org/t/creation-of-dummy-ipv6-ip-address-during-kickstart/5060 "2022-01-07T12:55:04Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![S1lv3rW1z4rd](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/s1lv3rw1z4rd/32/1586_2.png) [@S1lv3rW1z4rd](https://forums.rockylinux.org/u/S1lv3rW1z4rd)\ **Post date:** [January 7, 2022, 12:55pm UTC](https://forums.rockylinux.org/t/creation-of-dummy-ipv6-ip-address-during-kickstart/5060/1 "2022-01-07T12:55:04Z")
Hi, We’re trying to create ipv6 loopback IP addresses in Rocky 8 during the kickstart with a shell script. The goal would be that these IP’s are available on first boot. Previously in CentOS 7 we added them to the ifcfg-lo but this doesn’t work any longer. So we tried the following by executing this script during kickstart installation via Foreman; > #!/bin/sh > #an IPV6 adress for each instance > #The …99 adress will be used for the multi instance when using the apache reverse proxy (in the future) > > echo “]] \ Adding IPV6 address to loopback interface for internal use” > > nmcli c add type dummy ifname gateway-multi save yes > ls -l /etc/NetworkManager/system-connections > > for x in 0001 0002 > do > nmcli c modify dummy-gateway-multi +ipv6.addresses 2001:0db8:1234:0000:0000:0000:0000:$x/128 > done > > ls -l /etc/NetworkManager/system-connections > nmcli c modify dummy-gateway-multi ipv6.addr-gen-mode eui64 > nmcli c modify dummy-gateway-multi ipv6.method static > ls -l /etc/NetworkManager/system-connections > nmcli c show dummy-gateway-multi > ls -l /etc/NetworkManager/system-connections > ifconfig > systemctl restart NetworkManager > ls -l /etc/NetworkManager/system-connections > ifconfig > ls -l /etc/NetworkManager/system-connections > > echo “]] \ Adding IPV6 address done” Some lines in the shell script have been added for troubleshooting purpose. Basically it comes down to these commands; > nmcli c add type dummy ifname gateway-multi save yes > nmcli c modify dummy-gateway-multi +ipv6.addresses 2001:0db8:1234:0000:0000:0000:0000:0001/128 > nmcli c modify dummy-gateway-multi ipv6.addr-gen-mode eui64 > nmcli c modify dummy-gateway-multi ipv6.method static > nmcli c show dummy-gateway-multi > ifconfig If above commands are executed in an already build vm they are persistent and the IP’s are still present after reboot. However our executed scripts logs the following; ![MicrosoftTeams-image (1)](https://us1.discourse-cdn.com/flex020/uploads/rockylinux/original/2X/c/c1c7d6ac519b2d7e323ba40ad7e36fd3ce8e5f30.png) ls command shows that the file is not actually created in /etc/NetworkManager/system-connections. And also nmcli command show the ipv6 addresses while ifconfig only shows the interface but the additional ipv6 addresses are not there. Once booted, interface dummy-gateway-multi is nowhere to be found. What are we doing wrong ? ---
**Author:** ![jlehtone](https://avatars.discourse-cdn.com/v4/letter/j/e9a140/32.png) [@jlehtone](https://forums.rockylinux.org/u/jlehtone)\ **Post date:** [January 7, 2022, 1:20pm UTC](https://forums.rockylinux.org/t/creation-of-dummy-ipv6-ip-address-during-kickstart/5060/2 "2022-01-07T13:20:41Z")
First, I have no idea what a “loopback address” is (apart from the localhost.localdomain). Second, one of the default packages makes NetworkManager to support the RHEL legacy /etc/sysconfig/network-scripts/ifcfg-\* format. As example, an system, where install did not define (and save) connections does autodefine connections for interfaces by default (but does not save). Once you modify such connection, it will be saved as /etc/sysconfig/network-scripts/ifcfg-$devname nmcli can give multiple options on oneliner: ```auto nmcli c add type dummy ifname gateway-multi ipv6.method static +ipv6.addresses 2001:0db8:1234:0000:0000:0000:0000:0001/128 ipv6.addr-gen-mode eui64 ``` It makes sense to initialize all values on creation, rather than modify later? RHEL doc says that you have to set both IPv4 and IPv6: [Chapter 24. Creating a dummy interface Red Hat Enterprise Linux 8 | Red Hat Customer Portal](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/creating-a-dummy-interface_configuring-and-managing-networking) For example: ```auto nmcli c add type dummy ifname gateway-multi ipv4.method disabled ipv6.method static +ipv6.addresses 2001:0db8:1234:0000:0000:0000:0000:0001/128 ipv6.addr-gen-mode eui64 ``` The _net-tools_ (includes ifconfig) is described _obsolete_ – since _iproute2_ was introduced couple decades ago. When you write ‘kickstart’, does that use Red Hat’s ‘Kickstart’? That kickstart can define/configure connections: [Appendix B. Kickstart commands and options reference Red Hat Enterprise Linux 8 | Red Hat Customer Portal](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/performing_an_advanced_rhel_installation/kickstart-commands-and-options-reference_installing-rhel-as-an-experienced-user#kickstart-commands-for-network-configuration_kickstart-commands-and-options-reference) Not sure whether it can create a dummy. My current procedure is to do only a minimal install and then run _Ansible_ play (in “already built” system) that installs and configures everything, including additional network touches. ---
**Author:** ![S1lv3rW1z4rd](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/s1lv3rw1z4rd/32/1586_2.png) [@S1lv3rW1z4rd](https://forums.rockylinux.org/u/S1lv3rW1z4rd)\ **Post date:** [January 10, 2022, 1:52pm UTC](https://forums.rockylinux.org/t/creation-of-dummy-ipv6-ip-address-during-kickstart/5060/3 "2022-01-10T13:52:03Z")
Thanks for your feedback but it looks like what we want to achieve is no longer possible during kickstart/anaconda. So we will have to define the network interface after the build is complete. ---
**Author:** ![brian](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.rockylinux.org/brian/32/5777_2.png) [@brian](https://forums.rockylinux.org/u/brian)\ **Post date:** [August 25, 2023, 3:57am UTC](https://forums.rockylinux.org/t/creation-of-dummy-ipv6-ip-address-during-kickstart/5060/4 "2023-08-25T03:57:48Z")