With show ip ospf database database-summary you get the type and number of routes you have and with the formulas below you can figure out the size you are occupying with the LSAs OSPF Memory Calculation All fields in the LSA's were calculated from what RFC 1247 states. Following constants were used
#define RLS_HEADER 24
#define RL_SIZE 12
#define NLS_HEADER 24
#define SIZE_ROUTER 4
#define SUMM_MEMORY 28
#define EXT_MEMORY 36
#define ASBR_MEMORY 28
/* calc for Router Link State = (header + (link_size * #of links))* No fo routers */
RLS = (RLS_HEADER + (RL_SIZE*(three/one+1))) * one;
/* 1 is added because three/one rounds down */
/* calc for Network Links State = (NLS_header + (No fo routers on each seg * 4 bytes))* no multi acces net */
NLS = (NLS_HEADER + (four_2*SIZE_ROUTER)) * four_1;
/* calc for summary link state = header * three */
SLS = SUMM_MEMORY * three;
/* calc for external link states = header * five */
ELS = EXT_MEMORY * five ;
/* calc for ASBR LS = header (assuming one ASBR) */
ASBR = ASBR_MEMORY;
RLS---Router Link State
NLS---Network Link State
SLS---Summary Link State
ELS---External Link State.
ASBR--Autonomous System Border Router.
The folowing RFC will give u a detailed info on this:
http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1247.html
