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Showing posts from 2012

How to Configure DHCP on a Cisco Router or Cisco Switch?

1. Configure an IP address on the router’s Ethernet port, and bring up the interface. Router(config)# interface ethernet0/0 Router(config-if)#ip address 1.1.1.1 255.0.0.0 Router(config-if)# no shutdown 2. Create a DHCP IP address pool for the IP addresses you want to use. Router(config)# ip dhcp pool mypool 3. Specify the network and subnet for the addresses you want to use from the pool. Router(dhcp-config)# network 1.1.1.0 /8 4. Specify the DNS domain name for the clients. Router(dhcp-config)#domain-name mydomain.com 5. Specify the primary and secondary DNS servers. Router(dhcp-config)#dns-server 1.1.1.10 1.1.1.11 6. Specify the default router (i.e., default gateway). Router(dhcp-config)#default-router 1.1.1.1 7. Specify the lease duration for the addresses you’re using from the pool. Router(dhcp-config)#lease 7 8. Exit Pool Configuration Mode . Router(dhcp-config)#exit

Disabling Unneeded Services

Step 1: Configure the Physical Interface Because this lab uses only one router, you will simulate an active FastEthernet connection by activating the interface and applying the no keepalive command to initiate an “always up” state, regardless of the existence of a device at the remote end. Normally, you would not use the no keepalive command on a routed interface, except in special circumstances. In this lab, you will use it only for simulation purposes. Configure the R1 physical interface using the IP address shown in the topology diagram. Use the no keepalive command in interface configuration mode, and then use the no shutdown command to activate the interface. Because you have disabled keepalives, the interface status displays as link state (Layer 1) and line protocols state (Layer 2) “up,” even if it is not connected to an external device. R1(config)# interface fastethernet0/0 R1(config-if)# ip address 192.168.10.1 255.255.255.0 R1(config-if)# no keepalive R1(config-if)# no s

REVERSE TELNET ON AUX PORT

  Requirement :   Need   to   configure   reverse telnet   via   AUX   port. Connect one router's aux port to another device's console port, and telnet to the router.Use reverse telnet to connect to the other device's console via your aux port   Setup   :   Here's how to set it up. 1.       Connect your router's aux port to another device's console port using a Cisco flat crossover cable. 2.       Telnet to your router, enable, and set the aux port up as follows:   R1#conf t R1(config)# line aux 0 R1(config-line)# modem InOut R1(config-line)# transport preferred all R1(config-line)# transport input all R1(config-line)# transport output all R1(config-line)# end 3.       Make sure you have an address on your lo0 interface, and the interface is up. R1#conf t R1(config)#int   lo0 R1(config-if)#ip   add   127.0.0.1 255.255.255.0 Execution : 1)       Come back in enable mode, find out the line number of your AUX port with “show   line”. It will look something l