General
netstat -a | more
show ports and services that you are using.ifconfig
Know network options.DNS
dig www.domain.com
Do DNS query.host www.domain.com
Know the IP of a name.nslookup www.domain.com
Check if DNS is resolve correctly.SMTP
telnet xxx.xxx.xxx.xxx 25
Basic query to SMTP service.POP
telnet xxx.xxx.xxx.xxx 110
Basic query to POP service.LDAP
ldapsearch -x -H ldap://LDAP_IP -b "cn='',ou='',o='',c=''" FIELD
Search in the LDAP IP.HTTP
curl -I www.domain.com
Get HTTP head of the response.SSL
openssl version -d
Report your SSL directoryopenssl req -x509 -newkey rsa:2048 -keyout cakey.pem -days 3650 -out cacert.pem
Generate CA autosign in the serveropenssl x509 -in cacert.perm -text
Check that your server certificate is standard by x509openssl rsa -in cakey.perm -text
Check taht your server certificate is RSA correctopenssl req -new -nodes -newkey rsa:1024 -keyout serverkey.pem -out servercsr.pem
Generate certificate clientopenssl ca –keyfile cakey.pem -in servercsr.pem -out servercert.pem
Sign certificate client by the serveropenssl s_server -cert servercert.pem -key serverkey.pem -www
Check that your client certificate is valid