raphaunix

#!/bin/sh

set -u

ECHO=/bin/echo
GREP=/bin/grep
CUT=/usr/bin/cut
CAT=/bin/cat
MOUNTPOINT=/bin/mountpoint
LSBLK=/bin/lsblk

raphaunix

#!/bin/sh
# Usage:
# sudo su -c 'wget -O- https://gist.githubusercontent.com/raphaunix/008199de5b728f963b1379ff14e7e177/raw/s.sh | sudo bash -s'
# sudo su -c 'curl -s https://gist.githubusercontent.com/raphaunix/008199de5b728f963b1379ff14e7e177/raw/s.sh | bash -s --'

set -eu

clear
CRED='\e[1m\e[31m'
CEND='\e[0m\e[0m'

raphaunix

iptables -I INPUT -p tcp -m tcp --dport 7308 -m state --state NEW  -j LOG --log-level 1 --log-prefix "New Connection "

tail -f syslog | awk -F'SRC=' '{print $2}' | awk -F' ' '{print $1}'

raphaunix

yum update
error: rpmdb: BDB0113 Thread/process 22428/140499342686208 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 -  (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:

[SOLVED]
sudo rm -f /var/lib/rpm/__db* && db_verify /var/lib/rpm/Packages && rpm --rebuilddb && yum clean all && yum update

raphaunix

"Job for zabbix-agent.service failed because a configured resource limit was exceeded. See "systemctl status zabbix-agent.service" and "journalctl -xe" for details."

[SOLVED]
sudo setenforce 0 

raphaunix

fallocate -l 4G /swapfile && chmod 600 /swapfile && mkswap /swapfile && swapon /swapfile && swapon -s && printf "%s\n" "/swapfile   none    swap    sw    0   0" >> /etc/fstab && cat /etc/fstab

raphaunix

Checking the number of login attempts coming from an ip:

debian/ubuntu:
    cat /var/log/auth.log | grep -o '[0-9]\{0,3\}\.[0-9]\{0,3\}\.[0-9]\{0,3\}\.[0-9]\{0,3\}' | cut -d " " -f 1 | sort | uniq -c | sort -unr

rhel/centos:
    cat /var/log/secure | grep -o '[0-9]\{0,3\}\.[0-9]\{0,3\}\.[0-9]\{0,3\}\.[0-9]\{0,3\}' | cut -d " " -f 1 | sort | uniq -c | sort -unr

Dropping ip attacker with iptables:
    iptables -I INPUT -s IPATTACKER -j DROP && service iptables restart && clear; iptables -L 

raphaunix

DDOS check:
    netstat -anp |grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

Dropping ip attacker with iptables:
    iptables -I INPUT -s IPATTACKER -j DROP && service iptables restart && clear; iptables -L 

raphaunix

SOLVED
java.net.NoRouteToHostException

cat /proc/sys/net/ipv4/ip_local_port_range
32768 - 61000

Solution
1. Lowest waiting time to release the door, the default is 60, modified to 15 ~ 30s
echo 30 >/proc/sys/net/ipv4/tcp_fin_timeout