nmap - checking open ports and footprinting
MSF - Metasploit framework
DIRB - enumerate files on webserver
Wireshark - network analytics
Wfuzz - bruteforcing web applications
sqlmap - detection and exploitation of SQL injection flaws

Network debug

Chek for crc error on network interface
ethtool -S "interface" |grep crc
netstat -i
ip -s link show
ip r s
ip route show table all
ip route del xx.yy.xx.yy/xx dev wlp3s0