${lcp_failure:+lcp-echo-interval $lcp_interval lcp-echo-failure $lcp_failure $lcp_adaptive} \
${ipv6:++ipv6} \
${autoipv6:+set AUTOIPV6=1} \
${lcp_failure:+lcp-echo-interval $lcp_interval lcp-echo-failure $lcp_failure $lcp_adaptive} \
${ipv6:++ipv6} \
${autoipv6:+set AUTOIPV6=1} \