usr/src/include/protocols/routed.h

/*      routed.h        82/06/05        4.4     */
/*
 * Routing Information Protocol
 *
 * Derived from Xerox NS Routing Information Protocol
 * by changing 32-bit net numbers to sockaddr's and
 * padding stuff to 32-bit boundaries.
 */
struct netinfo {
        struct  sockaddr rip_dst;       /* destination net/host */
        int     rip_metric;             /* cost of route */
};

struct rip {
        u_char  rip_cmd;                /* request/response */
        u_char  rip_res1[3];            /* pad to 32-bit boundary */
        union {
                struct  netinfo ru_nets[1];     /* variable length... */
                char    ru_tracefile[1];        /* ditto ... */
        } ripun;
#define rip_nets        ripun.ru_nets
#define rip_tracefile   ripun.ru_tracefile
};

#define RIPCMD_REQUEST          0x1     /* want info */
#define RIPCMD_RESPONSE         0x2     /* responding to request */
#define RIPCMD_TRACEON          0x3     /* turn tracing on */
#define RIPCMD_TRACEOFF         0x4     /* turn it off */

#define IPPORT_ROUTESERVER      520     /* well-known port */
#define HOPCNT_INFINITY         16      /* per Xerox NS */
#define MAXPACKETSIZE           512     /* max broadcast size */

/*
 * Timer values used in managing the routing table.
 * Every update forces an entry's timer to be reset.  After
 * EXPIRE_TIME without updates, the entry is marked invalid,
 * but held onto until GARBAGE_TIME so that others may
 * see it "be deleted".  If there's a reason to look for network
 * interface transitions do so every CHECK_INTERVAL seconds.
 */
#define TIMER_RATE              30      /* alarm clocks every 30 seconds */
#define GARBAGE_TIME            210     /* time to garbage collect */
#define EXPIRE_TIME             180     /* time to mark entry invalid */
#define SUPPLY_INTERVAL         30      /* time to supply tables */
#define CHECK_INTERVAL          300     /* time to check for new interfaces */