Category Archives: Networking

Cisco CSR1000v Router as NAT Instance on AWS

We’ll use the below scanrio in this tutorial in which we’ll configureĀ Cisco CSR1000v Router as custom NAT Instance within our vpc on AWS.

NAT

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Authenticate the Cisco Devices using FreeRADIUS on Ubuntu

secnario

We want to authenticate and authorize the user on Cisco devices using the Free Radius on Ubuntu Server. In this tutorial, we want to create two users, Arbab and Ali. Arbab have full access to Cisco devices (privilege level 15) while Ali has custom access (like show commands including show running and interface configurations) only.

FreeRADIUS configuration on Ubuntu:

Install FreeRADIUS by using the following command:

sudo apt-get install freeradius

1

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OpenVPN Client Configuration on Ubuntu 12.04

To use the Ubuntu as OpenVPN client, install these packages:

sudo apt-get install network-manager-openvpn

2

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Authenticate the Cisco Devices using Active Directory

Router and AD copy

We want to authenticate and authorize the user on Cisco devices using the Microsoft Active Directory. In this tutorial, we want to create two Active Directory groups, Network Admin and NetworkĀ Tech. Network Admin have full access to Cisco devices (privilege level 15) while Network Tech have custom access (like show commands including show running and interface configurations) only.

arbab belong to the Network Admin group

aliĀ Ā belong to the Network Tech group

Network Policy and Access Services:

Before starting this tutorial, I assume that you have installed the Active Directory and it is up and running. Let’s start the tutorial by adding the NPS Role:

Start ->Ā Administrative Tools -> Server Manager

1 copy

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How to Change the Network Cards Priority in Windows 7

wire-wireless

Scenario:

We are connecting with the two different networksĀ using theĀ wired and wireless cards simultaneously . We want to access the local resources (e.g: file server, print server, application server etc) using the wired connection while Ā want to browse the Internet using the wireless connection.

To check the defaultĀ Network Cards Priority, open up a command prompt and issue this command:

netstat -r

2

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Multiple DHCP Servers on single Mikrotik

mikrotikScenario:

Mikrotik dhcp server with 3 network cards (LAN,Wireless,WAN), WAN is connected toĀ Internet, Wireless is connected to the 10.10.10.0/24 subnetĀ and serve as dhcp server Ā while LAN interface serve for 172.16.10.0/24 subnet.

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Configure Mikrotik DHCP to assign ip address to only authorized client(s) {2nd Method}

ToĀ achieveĀ the same goal, you can also consult this postĀ and decide yourself that which method suit you better!

mikrotik

Scenario:

Mikrotik is working as dhcp, dns, and default gateway for local network.

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How to setup vsftpd FTP with SSL on Ubuntu 12.04

This tutorial teaches you, how to setup vsftpd server on LinuxĀ based dedicatedĀ Web server. The tutorial also teaches you how to add the ftp users and lock the directory to individual users(In this scenario,lock the users into their individual web directory).

In Ubuntu 12.04, vsftpd with chrooted users gives the following error message:

500 OOPS: vsftpd: refusing to run with writable root inside chroot ()

To overcome this problem, we need to add the following vsftpd PPA:

sudo add-apt-repository ppa:thefrontiergroup/vsftpd

Updates the local repository (package list):

sudo apt-get update

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How to convert PPK file to ssh remote server in ubuntu

To convert the ppk file into openssh standard, we need to install the puttygen tool:

sudo apt-get install putty

Here is the ppk key that we want to convert:

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OSPF routing between Cisco,Ubuntu,CentOS and Mikrotik Router!

Scenario:

  • Routers: 1 Ubuntu Linux with 3 nics, 1 Centos Linux with 3 nics, 1 Cisco 3640 Router with 3 FastEthernet interfaces and 1 Mikrotik Router with 2 interfaces.
  • Clients: 3 Windows Xp with 1 nic.
IP Details

All the Routers in this scenario have a default password of ā€œzebraā€œ.

Cisco Router:

  • fe0/0: 10.10.10.1/24
  • fe1/0:10.10.50.1 /24
  • fe2/0: Getting through DHCP

UbuntuRouter:

  • eth0: 10.10.10.2/24
  • eth1: 172.16.10.1/24
  • eth2: 10.10.100.1/24

CentOSRouter:

  • eth0: 172.16.10.2/24
  • eth1: 192.168.10.1/24
  • eth2: 10.10.150.1/24

Mikrotik Router:

  • ether1: 192.168.10.2/24
  • ether2: 10.10.200.1/24

Clients:

  • Ubuntu-Desktop: 10.10.50.50/24
  • WinXP-1: 10.10.100.50/24
  • WinXP-2: 10.10.150.50/24
  • WinXP-3: 10.10.200.50/24

Cisco Router Configuration:

UbuntuRouter Configuration:

Restart the Router!!!

CentOSRouter Configuration:

Restart the Router!!!

Mikrotik Router Configuration:

Neighbor verification from Routers:

Route verification from Routers:

Test from Clients:

Make a simple test from Ubuntu-Desktop.

Make a simple test fromĀ WinXP-1.

Make a simple test fromĀ WinXP-2.

Make a simple test fromĀ WinXP-3.

Configure NAT on Cisco Router:

This is just a bonus section, in which we will configure the NAT on Cisco router and also propagate the default route in OSPF. I connect my Cisco Router to DSL Modem and configure it so that it will take IP address through DHCP, as well as configure the inside and outside interface for NAT.

Lazy man access -list for NAT (This is not the perfect access list):

NAT Overload:

Originate the default route in OSPF:

Verify the last resort information on Cisco Router:

Check default route information on all routers šŸ™‚

Hope this will help you!

Please Remember me in your prayers!

Enjoy šŸ™‚