root@azvir-2023-09-26:/etc# ls
adduser.conf                   cron.daily           group            ldap            manpath.config       passwd                   rmt           supervisor
alternatives                   cron.hourly          group-           ld.so.cache     mime.types           passwd-                  rpc           sysctl.conf
apm                            cron.monthly         grub.d           ld.so.conf      mke2fs.conf          perl                     rsyslog.conf  sysctl.d
apparmor                       crontab              gshadow          ld.so.conf.d    modprobe.d           pm                       rsyslog.d     systemd
apparmor.d                     cron.weekly          gshadow-         legal           modules              popularity-contest.conf  screenrc      terminfo
apt                            dbus-1               gss              libaudit.conf   modules-load.d       profile                  securetty     timezone
at.allow                       debconf.conf         hdparm.conf      libnl-3         motd                 profile.d                security      tmpfiles.d
bash.bashrc                    debian_version       host.conf        locale.alias    mtab                 protocols                selinux       ucf.conf
bash_completion                default              hostname         locale.gen      nanorc               python                   services      udev
bash_completion.d              deluser.conf         hosts            localtime       netplan              python2.7                shadow        ufw
bindresvport.blacklist         depmod.d             hosts.allow      logcheck        network              python3                  shadow-       updatedb.conf
binfmt.d                       dhcp                 hosts.deny       login.defs      networkd-dispatcher  python3.6                shells        update-manager
ca-certificates                dictionaries-common  init.d           logrotate.conf  NetworkManager       rc0.d                    skel          update-motd.d
ca-certificates.conf           dpkg                 initramfs-tools  logrotate.d     networks             rc1.d                    ssh           vim
ca-certificates.conf.dpkg-old  emacs                inputrc          lsb-release     newt                 rc2.d                    ssl           vtrgb
calendar                       environment          iproute2         ltrace.conf     nginx                rc3.d                    subgid        wgetrc
cloud                          fonts                iptables         machine-id      nsswitch.conf        rc4.d                    subgid-       X11
console-setup                  fstab                issue            magic           opt                  rc5.d                    subuid        xdg
cracklib                       fuse.conf            issue.net        magic.mime      os-release           rc6.d                    subuid-       zsh_command_not_found
cron.allow                     gai.conf             kernel           mailcap         pam.conf             rcS.d                    sudoers
cron.d                         groff                kernel-img.conf  mailcap.order   pam.d                resolv.conf              sudoers.d
root@azvir-2023-09-26:/etc# cat /etc/resolv.conf
nameserver 77.88.8.25
root@azvir-2023-09-26:/etc# ping 77.88.8.25
PING 77.88.8.25 (77.88.8.25) 56(84) bytes of data.
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
^Z
[3]+  Stopped                 ping 77.88.8.25
root@azvir-2023-09-26:/etc# iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:1322
ACCEPT     udp  --  anywhere             anywhere             udp spt:domain dpts:1024:65535
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http

Chain FORWARD (policy DROP)
target     prot opt source               destination         

Chain OUTPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:https
root@azvir-2023-09-26:/etc# man ping
root@azvir-2023-09-26:/etc# tcpdump -help
tcpdump version 4.9.3
libpcap version 1.8.1
OpenSSL 1.1.1  11 Sep 2018
Usage: tcpdump [-aAbdDefhHIJKlLnNOpqStuUvxX#] [ -B size ] [ -c count ]
		[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]
		[ -i interface ] [ -j tstamptype ] [ -M secret ] [ --number ]
		[ -Q in|out|inout ]
		[ -r file ] [ -s snaplen ] [ --time-stamp-precision precision ]
		[ --immediate-mode ] [ -T type ] [ --version ] [ -V file ]
		[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z postrotate-command ]
		[ -Z user ] [ expression ]
root@azvir-2023-09-26:/etc# tcpdump 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
^Z
[4]+  Stopped                 tcpdump
root@azvir-2023-09-26:/etc# ifconfig

Command 'ifconfig' not found, but can be installed with:

apt install net-tools

root@azvir-2023-09-26:/etc# uptime
 16:10:00 up 23:36,  1 user,  load average: 0.00, 0.00, 0.00
root@azvir-2023-09-26:/etc# iptables -F
client_loop: send disconnect: Broken pipe

<
Previous Post
TCP
>
Next Post
Connection to device