In simple words Netcat is a Unix utility which reads and writes data across network connections, using TCP or UDP protocol. That’s it. But because its such a reliable back end tool which offers rich features for network debugging and exploration it would stupid not learn about it. It is used from the command terminal …
smbclient is samba client with an “ftp like” interface. It is a useful tool to test connectivity to a Windows share. It can be used to transfer files, or to look at share names. In addition, it has a nifty ability to ‘tar’ (backup) and restore files from a server to a client and visa …
ICMP codes often come handy when you are trying to find the status of a remote host. ICMP Type Message 0 Echo reply 3 Destination unreachable 4 Source quench 5 Redirect 8 Echo 9 Router advertisement 10 Router selection 11 Time exceeded 12 Parameter problem 13 Timestamp 14 Timestamp reply 15 Information request 16 Information …
IP Sec is of the protocol suits used to provide data security in transit like SSL/TLS. SSL/TLS are generally used when data has to be secured between a mobile client. Before we dive deep into IPsec working there are couple of things that need to be fleshed out regarding IPsec. IPsec has two modes of …
AAA stands for authentication Authorization and Accounting. We all know the importance of AAA services in any network. There are numbers of ways to implement AAA services. The most commonly used are Tacacs+ Radius TACACS+ RADIUS Terminal Access Control Access Control Server Remote Authentication Dial-In User services. Cisco proprietary protocol open standard protocol It uses …
Both TCP and UDP are protocols at the Transport layer (of both OSI and TCP/IP model) but why we need both of them? The answer is: + TCP is slower but reliable+ UDP is faster but unreliable In most cases we will want to be reliable in web accessing, email communicating, file uploading… as we …
File transfer protocol is used to transfer files between a client and a server. FTP uses 2 basic channels to operate. Command Channel Data Channel Command Channel is used by the server or the client to send commands and receive replies. The Data Channel transmits the actual data requested. FTP can operate either in passive …
As an administrator of a network, you have just completed all the configuration and they are working nicely. Now maybe the next thing you want to do is to set up something that can alert you when something goes wrong or down in your network. Syslog is an excellent tool for system monitoring and is …
A device needs an IP address to communicate on the network. One way to assign an IP address to the device is to configure it statically but if you are deploying a large infrastructure, configuring each device manually becomes impractical. Dynamic host configuration protocol (DHCP) comes to rescue. When a client boots up for the …
FTP 20, 21 SSH 22 Telnet 23 SMTP 25 DNS 53 DHCP 67, 68 TFTP 69 HTTP 80 POP3 110 NNTP 119 NTP 123 IMAP4 143 LDAP 389 HTTPS 443 IMAPS 993 RADIUS 1812 RDP 3389 IKE Phase 1 UDP 500 IPsec phase 50