Level 4 is not valid for the NetServerEnum2 call.

struct server_info_4 {
     unsigned char                 sv4_name[CNLEN+1];
     unsigned char                 sv4_version_major;
     unsigned char                 sv4_version_minor;
     unsigned long                 sv4_type;
     unsigned char LSFAR * LSPTR   sv4_comment;
     unsigned long                 sv4_ulist_mtime;
     unsigned long                 sv4_glist_mtime;
     unsigned long                 sv4_alist_mtime;
     unsigned short                sv4_users;
     unsigned short                sv4_disc;
     unsigned char LSFAR * LSPTR   sv4_alerts;
     unsigned short                sv4_security;
     unsigned short                sv4_auditing;
     unsigned short                sv4_numadmin;
     unsigned short                sv4_lanmask;
     unsigned short                sv4_hidden;
     unsigned short                sv4_announce;
     unsigned short                sv4_anndelta;
     unsigned char                 sv4_guestacct[UNLEN + 1];
     unsigned char                 sv4_pad1;
     unsigned char LSFAR * LSPTR   sv4_userpath;
     unsigned short                sv4_chdevs;
     unsigned short                sv4_chdevq;
     unsigned short                sv4_chdevjobs;
     unsigned short                sv4_connections;
     unsigned short                sv4_shares;
     unsigned short                sv4_openfiles;
     unsigned short                sv4_sessopens;
     unsigned short                sv4_sessvcs;
     unsigned short                sv4_sessreqs;
     unsigned short                sv4_opensearch;
     unsigned short                sv4_activelocks;
     unsigned short                sv4_numreqbuf;
     unsigned short                sv4_sizreqbuf;
     unsigned short                sv4_numbigbuf;
     unsigned short                sv4_numfiletasks;
     unsigned short                sv4_alertsched;
     unsigned short                sv4_erroralert;
     unsigned short                sv4_logonalert;
     unsigned short                sv4_accessalert;
     unsigned short                sv4_diskalert;
     unsigned short                sv4_netioalert;
     unsigned short                sv4_maxauditsz;
     unsigned char LSFAR * LSPTR   sv4_srvheuristics;
     unsigned long                 sv4_auditedevents;
     unsigned short                sv4_autoprofile;
     unsigned char LSFAR * LSPTR   sv4_autopath;
     unsigned char LSFAR * LSPTR   sv4_cell;
     unsigned char LSFAR * LSPTR   sv4_resdom;

};

where: