# Apply IPv6 / ND configuration
HOPLIMIT=$(cat /proc/sys/net/ipv6/conf/$device/hop_limit)
- [ "$RA_HOPLIMIT" -gt "$HOPLIMIT" ] && echo "$RA_HOPLIMIT" > /proc/sys/net/ipv6/conf/$device/hop_limit
- [ "$RA_MTU" -gt 0 ] && echo "$RA_MTU" > /proc/sys/net/ipv6/conf/$device/mtu
- [ "$RA_REACHABLE" -gt 0 ] && echo "$RA_REACHABLE" > /proc/sys/net/ipv6/neigh/$device/base_reachable_time_ms
- [ "$RA_RETRANSMIT" -gt 0 ] && echo "$RA_RETRANSMIT" > /proc/sys/net/ipv6/neigh/$device/retrans_time_ms
+ [ -n "$RA_HOPLIMIT" -a -n "$HOPLIMIT" ] && [ "$RA_HOPLIMIT" -gt "$HOPLIMIT" ] && echo "$RA_HOPLIMIT" > /proc/sys/net/ipv6/conf/$device/hop_limit
+ [ -n "$RA_MTU" ] && [ "$RA_MTU" -gt 0 ] && echo "$RA_MTU" > /proc/sys/net/ipv6/conf/$device/mtu
+ [ -n "$RA_REACHABLE" ] && [ "$RA_REACHABLE" -gt 0 ] && echo "$RA_REACHABLE" > /proc/sys/net/ipv6/neigh/$device/base_reachable_time_ms
+ [ -n "$RA_RETRANSMIT" ] && [ "$RA_RETRANSMIT" -gt 0 ] && echo "$RA_RETRANSMIT" > /proc/sys/net/ipv6/neigh/$device/retrans_time_ms
# TODO: $SNTP_IP $SIP_IP $SNTP_FQDN $SIP_DOMAIN
}