Rathena has no true ddos protection, what you can do is turn off the protection features in login_athena.conf
// Ipban features
ipban_enable: yes
// Dynamic password failure ipban system
// Ban user after a number of failed attempts?
ipban_dynamic_pass_failure_ban: yes
// Interval (in minutes) to calculate how many failed attempts.
ipban_dynamic_pass_failure_ban_interval: 5
// Maximum amount of failed attempts before banning.
ipban_dynamic_pass_failure_ban_limit: 7
// Time (in minutes) for ban duration.
ipban_dynamic_pass_failure_ban_duration: 5
// Interval (in seconds) to clean up expired IP bans. 0 = disabled. default = 60.
// NOTE: Even if this is disabled, expired IP bans will be cleaned up on login server start/stop.
// Players will still be able to login if an ipban entry exists but the expiration time has already passed.
ipban_cleanup_interval: 60
// Interval (in minutes) to execute a DNS/IP update. Disabled by default.
// Enable it if your server uses a dynamic IP which changes with time.
//ip_sync_interval: 10
// DNS Blacklist Blocking
// If enabled, each incoming connection will be tested against the blacklists
// on the specified dnsbl_servers (comma-separated list)
use_dnsbl: no
dnsbl_servers: bl.blocklist.de, socks.dnsbl.sorbs.net, ircbl.ahbl.org, safe.dnsbl.sorbs.net, sbl-xbl.spamhaus.org, tor.ahbl.org,
//New registration flood protection
//Number of new registration allowed
allowed_regs: 1
//Time in second before the counter for the number of registration is reset
time_allowed: 10
Check if there are imports such as
import: conf/inter_athena.conf
import: conf/import/login_conf.txt
and check them.
have a good day