ls -utla
Install nmap and check which ports are open.Centos 7
yum install nmap
now scan the ports with :
nmap -sT -O localhost
result:
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000083s latency).
rDNS record for 127.0.0.1: localhost.localdomain
Not shown: 972 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
25/tcp open smtp
53/tcp open domain
80/tcp open http
110/tcp open pop3
111/tcp open rpcbind
143/tcp open imap
443/tcp open https
783/tcp open spamassassin
993/tcp open imaps
995/tcp open pop3s
1080/tcp open socks
1081/tcp open pvuniwien
2005/tcp open deslogin
2009/tcp open news
3005/tcp open deslogin
3306/tcp open mysql
5432/tcp open postgresql
8009/tcp open ajp13
8080/tcp open http-proxy
8081/tcp open blackice-icecap
9009/tcp open pichat
9080/tcp open glrpc
9090/tcp open zeus-admin
9100/tcp open jetdirect
10024/tcp open unknown
10025/tcp open unknown
No exact OS matches for host (If you know what OS is running on it, see http://nmap.org/submit/ ).
TCP/IP fingerprint:
OS:SCAN(V=6.40%E=4%D=7/23%OT=21%CT=1%CU=41542%PV=N%DS=0%DC=L%G=Y%TM=59744F1
OS:C%P=x86_64-redhat-linux-gnu)SEQ(SP=101%GCD=1%ISR=105%TI=Z%TS=A)SEQ(SP=10
OS:1%GCD=1%ISR=106%TI=Z%II=I%TS=A)OPS(O1=MFFD7ST11NW7%O2=MFFD7ST11NW7%O3=MF
OS:FD7NNT11NW7%O4=MFFD7ST11NW7%O5=MFFD7ST11NW7%O6=MFFD7ST11)WIN(W1=AAAA%W2=
OS:AAAA%W3=AAAA%W4=AAAA%W5=AAAA%W6=AAAA)ECN(R=Y%DF=Y%T=40%W=AAAA%O=MFFD7NNS
OS:NW7%CC=Y%Q=)T1(R=Y%DF=Y%T=40%S=O%A=S+%F=AS%RD=0%Q=)T2(R=N)T3(R=N)T4(R=Y%
OS:DF=Y%T=40%W=0%S=A%A=Z%F=R%O=%RD=0%Q=)T5(R=Y%DF=Y%T=40%W=0%S=Z%A=S+%F=AR%
OS:O=%RD=0%Q=)T6(R=N)T7(R=Y%DF=Y%T=40%W=0%S=Z%A=S+%F=AR%O=%RD=0%Q=)U1(R=Y%D
OS:F=N%T=40%IPL=164%UN=0%RIPL=G%RID=G%RIPCK=G%RUCK=G%RUD=G)IE(R=Y%DFI=N%T=4
OS:0%CD=S)
Network Distance: 0 hops
OS detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 12.22 seconds
now scan from external :
nmap -sT -O <ip>
result
Starting Nmap 7.50 ( https://nmap.org ) at 2017-07-23 09:30 CEST
Nmap scan report for web.site (<ip>)
Host is up (0.035s latency).
rDNS record for <ip>: mail. web.site
Not shown: 978 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
25/tcp open smtp
53/tcp open domain
80/tcp open http
110/tcp open pop3
111/tcp open rpcbind
135/tcp filtered msrpc
139/tcp filtered netbios-ssn
143/tcp open imap
443/tcp open https
445/tcp filtered microsoft-ds
993/tcp open imaps
995/tcp open pop3s
1080/tcp open socks
1081/tcp open pvuniwien
2009/tcp open news
3306/tcp filtered mysql
8009/tcp open ajp13
8081/tcp open blackice-icecap
9009/tcp open pichat
9080/tcp open glrpc
Device type: general purpose|media device|WAP|storage-misc
Running (JUST GUESSING): Linux 3.X|4.X|2.6.X (89%), Asus embedded (86%), Synology DiskStation Manager 5.X (86%)
OS CPE: cpe:/o:linux:linux_kernel:3 cpe:/o:linux:linux_kernel:4 cpe:/o:linux:linux_kernel:3.x cpe:/h:asus:rt-n56u cpe:/o:linux:linux_kernel:3.4 cpe:/o:linux:linux_kernel:3.10 cpe:/a:synology:diskstation_manager:5.2 cpe:/o:linux:linux_kernel:2.6.32
Aggressive OS guesses: Linux 3.2 – 4.8 (89%), Linux 3.18 (88%), Linux 3.16 (87%), Linux 3.13 or 4.2 (87%), XBMCbuntu Frodo v12.2 (Linux 3.X) (87%), ASUS RT-N56U WAP (Linux 3.4) (86%), Linux 3.13 (86%), Linux 3.12 (86%), Linux 3.8 – 3.11 (86%), Linux 4.10 (86%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 6 hops
OS detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 15.47 seconds
check now for LISTENING port:
Next, check for information about the port using netstat or lsof. To check for port 834 using netstat, use the following command:
netstat -anp | grep 834 |
result :
tcp 0 0 127.0.0.1:9168 127.0.0.1:47834 TIME_WAIT –
unix 2 [ ACC ] STREAM LISTENING 397083455 343/amavisd (ch1-av /var/spool/amavisd/amavisd.sock
unix 2 [ ] STREAM CONNECTED 481728342 25062/ruby
unix 3 [ ] STREAM CONNECTED 407881834 4920/dovecot
unix 2 [ ] STREAM CONNECTED 481808349 25062/ruby
The lsof command reveals similar information since it is also capable of linking open ports to services:
lsof -i | grep 834 |
To check if the port is associated with the official list of known services, type:
cat /etc/services |
to check the users log in use command : who
which process are running over a port eg 8080
netstat -nlp | grep 8080
Linux Command to check space disk and folder
To check Linux disk space use :
df -ha
To check Linux folder space use :
du -sh *
will not traverse any mount points it encounters. But if it is told to start at a mount point then it will do as requested.
du -shx *
for also hidden folder
du -sh .[^.]*
for hidden and not hidden
du -hs $(ls -A)
with threshold
du -h –threshold=10M .
du -h –threshold=10M –max-depth=0 * o du -h –threshold=10M –maxdepth=1 .
add | sort -n for sorting
How to show IP / MAC Address
The command to show ip and mac address in a network is : apr -a
? (192.168.1.1) at c4:a8:1d:3a:5:a5 on en1 ifscope [ethernet]
? (192.168.1.6) at cc:b1:1a:bb:63:d6 on en1 ifscope [ethernet]
Linux Centos 7 – Startup Services – Functions
systemctl disable httpd
Running systemctl disable removes the symlink to the service in /etc/systemd/system/*
systemctl status httpd
systemctl list-unit-files
systemctl start application.service
systemctl list-units –type=service
systemctl list-units –all –state=inactive
systemctl mask nginx.service
systemctl unmask nginx.service
systemctl edit nginx.service
To remove any additions you have made, either delete the unit’s .d configuration directory or the modified service file from /etc/systemd/system. For instance, to remove a snippet, we could type:
sudo rm -r /etc/systemd/system/nginx.service.d
To remove a full modified unit file, we would type:
sudo rm /etc/systemd/system/nginx.service
After deleting the file or directory, you should reload the systemd process so that it no longer attempts to reference these files and reverts back to using the system copies. You can do this by typing:
sudo systemctl daemon-reload
very usefull
https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units