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dot1x with Cisco Switch in GNS3 and CentOS Client

Today, I successfully completed a lab in GNS3 to work with dot1x wired authentication. In my lab, I used Cisco IOU L2 Image, FreeRADIUS Servers for remote authentication and CentOS 7 as a Client operating system.

In this post I will show my working configuration for Cisco L2 Switch, where "no ip routing" is configured. And a snapshot for from CentOS for network security setting to authenticate with 802.1x protocol.

On switch I used following configurations
My Cisco IOU L2 Image is

ACCESS-SW#sh version | in  Version
Cisco IOS Software, Solaris Software (I86BI_LINUXL2-IPBASEK9-M), Experimental Version 15.1(20130726:213425) [dstivers-july26-2013-team_track 105]

!
ACCESS-SW#show run
!
! output only dot1x related configuration
!
aaa new-model
aaa group server radius RADIUS1
 server name FreeRADIUS
aaa authentication dot1x default group RADIUS1 local
dot1x system-auth-control
! interface Ethernet3/0  switchport access vlan 10  switchport mode access  authentication port-control a…
Recent posts

Unable to Send Video Stream from VLC through Cisco Router

Today, while working on a multicast lab on Cisco Router. I build a lab to send multicast stream from one end to other end via VLC. I found that, while checking router with "show ip mroute" command , receiver PC was successful registering with Rendezvous Point Server to receive required multicast traffic but the Multicast source (Sender) was not registering with RP.
Upon a day's troubleshooting, i found in the packet capture that VLC Sender is sending multicast traffic with TTL Value 1, this is default behavior of VLC player and which will definitely be discarded by first receiving hop.
So I have to increase the TTL value little higher so that the multicast packets can traverse to some hops and reach the receiver.
To change the TTL value of the packet for sending multicast stream from VLC, you can change the default settings as per give below path and snap.

I also tried this in GNS3 and was working fine.

Go to Tools > Preferences >  Select ALL radio button at left …

Telnet Console Session to GNS3 Router and Switches Stops working

I am using GNS3 VM and connecting to it remotely from my laptop.

I was facing an issue where telnet to GNS3 routers/switches stopped working, though required router or switch was working properly and passing traffic but somehow it was disconnecting the telnet session. This issue happened when I directly close the telnet session,  or when my laptop is locked/logged off and upon re-connecting to GNS3 VM, I was unable to take console session to the router/switch until i restart the particular router/switch.

Solution to this problem was to properly "exit the console session with cli command" and not closing the putty window directly.
Or you can configure your router/switch for console timeout after some time.

a file I/O error has occurred while accessing vmware converter

While converting physical Windows 7 machine to Virtual machine of infrastructure type, I got this error. The error seems it is unable to read/write source or destination datastore.

I have installed VMware-converter-en-6.2.0-8466193 on Windows 7 physical machine with option locally selected. (not at server/client option)

All of my ESXi servers are connected to the vCenter Server, so I had to use vCenter Server's IP address to send this physical machine to the virtual world.

The issue i found was with the dns resolution to the vCenter Server's hostname. Since I am not using the same dns server on the Windows 7 client machine. So I updated the host entries manually for the vCenter Server's hosname to it IP address.

After adding dns eteries to the hostfile of windows 7, I am not getting this "a file I/O error has occurred while accessing vmware converter" and the migration has started.

How to check Gray-log current running version

If you planning to upgrade your graylog and want to see what your graylog current version is, here is how you can check it.
Go to the Graylog Web InterfaceClick on System/NodesUnder System/Nodes --- Click on the Nodes Scroll down to the 'System' Here you can see the current version of your graylog server



Graylog is restarting stuck with disk full

Graylog is restarting...
There is no Graylog web application running at the moment, please reload this page in a minute. It can take up to 1-2 minutes until all services are running properly. In case this is a permanent error, check the following:

Check if all services are running - sudo graylog-ctl status shows an overview of all running services
Check for errors in log files - Relevant services write log files here: /var/log/graylog/*/current
Ask for help - If there is no way to fix the issue ask for help:


I got this error on my Gray-log server, upon troubleshooting I found that the disk was 100% full and was unable to start elastic search mongodb and etcd while checking gray-log server status with command
#graylog-ctl status

Solution to this problem was obvious that I have to clean some disk space to get gray-log working again but what file should I delete was my next thought!

Upon googling I found that I could safely delete the old log files of elastic search to free up the space.

How to import Putty Saved Connections to mRemoteNG

Just started using mRemoteNG and its being very cool to connect to different remote connection with different protocols e.g Window Remote Desktop, VNC to Linux, SSH, HTTP connection etc. from a single application.

As new user I configured some remote desktop connection which was quite easy to figure out. But when I wanted to add SSH connections, it came in my mind to import all of the saved connections in the putty. But I couldn't figure it out how can it be done, though it was quite easy and here are the steps.


Open your mRemoteNGCreate a folder if you want segregation of multiple networksCreate a new connectionEnter the IP address of remote server under connection in Config paneUnder the config pane, select protocol "SSH version 2".  Once you select protocol to SSH version 2 you are given option to import putty sessions, as shown in the snap below.


In the above snap, I have imported CSR-AWS session from my saved sessions in Putty.