For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:p_conrad/openSUSE_Tumbleweed/home:p_conrad.repo
zypper refresh
zypper install mod_log_ipmask
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:p_conrad/openSUSE_Factory/home:p_conrad.repo
zypper refresh
zypper install mod_log_ipmask
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:p_conrad/15.5/home:p_conrad.repo
zypper refresh
zypper install mod_log_ipmask
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:p_conrad/15.4/home:p_conrad.repo
zypper refresh
zypper install mod_log_ipmask