RH 253: HOW TO INSTALL AND USE TELNET-SERVER

    TO INSTALL AND USE TELNET-SERVER


1. yum install xinetd
2. yum install telnet-server
3. service xinetd restart
4. chkconfig xinetd on
5. chkconfig --list all  |grep telnet
6. chkconfig telnet on


1. To connect to telnet server
---> telnet  <server.ip>
     Login:  user1
    passwd:  1



2. To Allow only particular client to connect to your server
--->  vim /etc/xinetd.d/telnet
      only_from =<clients.ip>        -->only this client is allowed to telnet



3. To stop a Client to access any type of xinetd based application
--> vim /etc/xinetd.conf
    no_access =<clients.ip>   ->this client cant access any xinetd application
--> service xinetd restart
---> telnet  <server.ip>        ->Not allowed



4. To stop a Client to access xinetd services in particular time
--> vim /etc/xinetd.conf
    access_times=10.00-12.00
--> service xinetd restart
---> telnet  <server.ip>        ->Not allowed if its not 10.00 to 12.00
---> telnet  <server.ip>        ->Allowed if time is b/w 10.00 to 12.00


--> tailf /var/log/secure     ->to check client connecting to your server.
     



  PORT MONITORING TOOLS

--->   SHOWS all applications running in local machine:

1. pkg:-net-tools-1.60-73             -> installed by default

   netstat  -tulpn  |grep <service>

   t->tcp  u->udp  l->listening  p->pid  n->numericip


2. pkg:-nmap-4.11-1.1           -> installed by default

   nmap   <ip.address>   |grep <service>


--->   SHOWS all applications running in entire network:


1. yum  install  wireshark
   Applications-->Internet-->wireshark-->capture
 
2. pkg:-tcpdump-3.9.4-11.el5       -> installed by default

   tcpdump  -c  <ip.address>   |grep <service>



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