Linux Cent OS Network Handy commands
tcp connection details:
sof -i
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ssh 15465 shgeorge 3r IPv4 628118962 0t0 TCP 172.21.1.100:42329->sdc-f5-dmz-ltm-01-ve.aim.local:ssh (ESTABLISHED)
lsof -i :ssh
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ssh 15465 shgeorge 3r IPv4 628118962 0t0 TCP 172.21.1.100:42329->sdc-f5-dmz-ltm-01-ve.aim.local:ssh (ESTABLISHED)
netstat -an | grep LISTEN
tcp 0 0 192.168.100.1:53 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:58811 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:199 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:5900 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN
tcp 0 0 :::22 :::* LISTEN
tcp 0 0 :::111 :::* LISTEN
tcp 0 0 :::58992 :::* LISTEN
unix 2 [ ACC ] STREAM LISTENING 17044 /var/lib/libvirt/qemu/sdc-securid-vm.deerfield.aim.local.monitor
unix 2 [ ACC ] STREAM LISTENING 221367479 /var/run/salt/minion/minion_event_942f3619a7_pull.ipc
unix 2 [ ACC ] STREAM LISTENING 14014 /var/run/rpcbind.sock
biggest top 10 directories
du -hs */ | sort -nr | head
biggest file
ls -lS | head
ls -lS | head
Linux Firewall
eg. permit udp/69
iptables -D INPUT -p udp –dport 69 -j ACCEPT
# Allows connections to SSH/SFTP/SCP
-A INPUT -j ACCEPT -p tcp --dport 22
# Allow ping
-A INPUT -p icmp -j ACCEPT
openssl
open key file
openssl req -nodes -newkey rsa:2048 -keyout myserver.key -out server.csr
search a file *.xml
find . -name *.xml
find files bigger than 10,000 bytes
find . -size +10000c -size -50000c -print
Top 10 directories
biggest top 10 directories
du -hs */ | sort -nr | head
Server Performance Using vmstat Command
vmstat -a
ZIP a file
gzip -ztf archive.tar.gz
unzip tar file
tar:
tar -tf archive.tar
No comments:
Post a Comment