Monthly Archives: May 2010

Netstat

netstat– to display TCP/UDP connections/interface statistics/routing table By default, this command displays all open sockets only. Options: -r: to display routing table -g: to display multicast group -i : to display all network interfaces -s: to display IP, ICMP, TCP, … Continue reading

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JUNOS CLI

Here is some basic CLI info in JUNOS. Connect to the Juniper router using roll-over cable. Default login username/password is root/ <empty> Unix Shell (C shell) – % Bourne shell – $ Operational mode –  “>” Configuration mode – “#” … Continue reading

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nmap

Nmap – network mapper tool to scan network device and get more information. By default: Nmap sends an ICMP echo request, a TCP SYN packet to port 443, a TCP ACK packet to port 80, and an ICMP timestamp request … Continue reading

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IOS switching mechanism

Process switching Fast switching CEF switching

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Configuring TACACS+ in Linux

Make sure TACACS+ server is installed in the linux system [RedHat is used for below testing] [root@server2 ~]# rpm -qa | grep tac_plus tac_plus-F4.0.3.alpha-7 [root@server2 ~]# Check whether tacacs+ service is running on the linux server; [root@server2 ~]# service tac_plus … Continue reading

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Configuring RADIUS in Linux

Make sure RADIUS server is installed in the linux system [RedHat used for testing] [root@server2 ~]# rpm -qa | grep radius freeradius-1.0.1-3.RHEL4.5 [root@server2 ~]# To make radius daemon start when the system boots up: “chkconfig radiusd on” If there is … Continue reading

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Configuring Syslog in Linux

We can configure a Linux host as syslog server to receive all logs from network devices. Basic information: Syslog server runs on UDP port 514. So, by default all network devices send syslogs with UDP DST port=514. Make sure the … Continue reading

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