Gnrc Router Solicitation Messages

Dear Devel’s,

I need to change the frequency on which router solicitation messages are sen’t or manually trigger them. I’ve found I can do this by modifying GNRC_SIXLOWPAN_ND_RTR_SOL_INT at sys/include/net/gnrc/sixlowpan/nd.h. But since the default value is already the minimum value specified by the RFC I’m wandering what would be the cleanest way to force a router solicitation message. Thanks in advance, cheers!