Documentation/networking/snmp_counter.rst

1078   nstatuser@nstat-b:~$ nc -lknv 0.0.0.0 9000
1079   Listening on [0.0.0.0] (family 0, port 9000)
1083   nstatuser@nstat-a:~$ nc -nv 192.168.122.251 9000
1084   Connection to 192.168.122.251 9000 port [tcp/*] succeeded!
1086 The server listened on tcp 9000 port, the client connected to it, they
1120   nstatuser@nstat-b:~$ nc -lkv 0.0.0.0 9000
1121   Listening on [0.0.0.0] (family 0, port 9000)
1125   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1126   Connection to nstat-b 9000 port [tcp/*] succeeded!
1130   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1131   Connection to nstat-b 9000 port [tcp/*] succeeded!
1164   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1165   Connection to nstat-b 9000 port [tcp/*] succeeded!
1215   nstatuser@nstat-a:~$ ss -o state established -i '( dport = :9000 or sport = :9000 )
1217   tcp      0          0               192.168.122.250:40654         192.168.122.251:9000
1246   port = 9000
1255 This python script listen on 9000 port, but doesn't read anything from
1260   nstatuser@nstat-a:~$ echo "hello" | nc nstat-b 9000
1288   port = 9000
1309   port = 9000
1333   sudo iptables -A INPUT -i ens3 -p tcp --destination-port 9000 -j DROP
1403   port = 9000
1419   port = 9000
1442 On the server, we run a program which listen on TCP port 9000, but
1447   port = 9000
1463   port = 9000
1502 On server, run the nc command, listen on port 9000::
1504   nstatuser@nstat-b:~$ nc -lkv 0.0.0.0 9000
1505   Listening on [0.0.0.0] (family 0, port 9000)
1509   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1510   Connection to nstat-b 9000 port [tcp/*] succeeded!
1523   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1655   nstatuser@nstat-a:~$ sudo tcpdump -c 1 -w /tmp/syn.pcap port 9000
1660   nstatuser@nstat-a:~$ nc nstat-b 9000
1662 As the nstat-b didn't listen on port 9000, it should reply a RST, and
1670 On nstat-b, we run nc to listen on port 9000::
1672   nstatuser@nstat-b:~$ nc -lkv 9000
1673   Listening on [0.0.0.0] (family 0, port 9000)
1675 On nstat-a, we blocked the packet from port 9000, or nstat-a would send
1678   nstatuser@nstat-a:~$ sudo iptables -A INPUT -p tcp --sport 9000 -j DROP
1695 On nstat-b, let nc listen on port 9000::
1697   nstatuser@nstat-b:~$ nc -lkv 9000
1698   Listening on [0.0.0.0] (family 0, port 9000)
1702   nstatuser@nstat-a:~$ sudo tcpdump -w /tmp/paws_pre.pcap -c 1 port 9000
1707   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1708   Connection to nstat-b 9000 port [tcp/*] succeeded!
1734 could create two sockets: one on port 9000, another on port 9001. Then
1736 numbers to match the port 9000 socket. Then we could trigger
1740 port 9000 and port 9001::
1742   nstatuser@nstat-b:~$ nc -lkv 9000
1743   Listening on [0.0.0.0] (family 0, port 9000)
1750   nstatuser@nstat-a:~$ nc -v nstat-b 9000
1751   Connection to nstat-b 9000 port [tcp/*] succeeded!
1772   nstatuser@nstat-a:~$ ss -ta '( dport = :9000 || dport = :9001 )' | tee
1774   ESTAB  0        0            192.168.122.250:50208       192.168.122.251:9000
1777 Run tcprewrite, change port 9001 to port 9000, change port 42132 to
1780 …nstatuser@nstat-a:~$ tcprewrite --infile /tmp/seq_pre.pcap --outfile /tmp/seq.pcap -r 9001:9000 -r…