rtable_ent()
- nsaddr_t dst
- destination
- nsaddr_t hop
- next hop
- uint metric
- distance
- uint seqnum
- last sequence number we saw
- double advertise_ok_at
- when is it okay to advertise this rt?
- bool advert_seqnum
- should we advert rte b/c of new seqnum?
- bool advert_metric
- should we advert rte b/c of new metric?
- Event* trigger_event
bool needs_advertised; bool needs_repeated_advert;
- uint last_advertised_metric
- metric carried in our last advert
- double changed_at
- when route last changed
- double new_seqnum_at
- when we last heard a new seq number
- double wst
- running wst info
- Event* timeout_event
- event used to schedule timeout action
- PacketQueue* q
- pkts queued for dst
class rtable_ent 
bool advert_metric 