Calin

Author Archives: Calin

IPsec VPN Mikrotik to Linux

After writing the Mikrotik IPsec VPN article and I got some questions about how Mikrotik will work with a Linux device to build an IPsec VPN. I did notice that the questions were more oriented for a copy / paste solution, so I’ll provide one that it’s working. If you need more details about why the solution is like it this, please let me know.
Also don’t forget to customize the solution as you need.

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New GNS3 1.0 Beta 1

It appears that there are some significant changes ongoing with GNS3:     As mentioned by the GNS3 CEO and co-founder Stephen Guppy on 11th of August 2014, the new GNS3 will be more polished and will migrate to a multi-vendor emulation platform. For those using this tool, it’s a well known fact that GNS3 […]

EGP

Today I came across an old Cisco router with original IOS image. Big surprise (at least for me) when I did check what routing protocols are supported on this router: I was out of the game, or better not even yet had discover the networking games, when the EGP was still out there and available […]

Troubleshooting with Wireshark [Riverbed lab kit]

A while ago I attended a Wireshark webinar from Riverbed in which they presented the tool, some beginner and intermediate users troubleshooting scenarios and some lab kit. Now I got an e-mail that they made it available for download at http://www.riverbed.com/wireshark-virtual-tour Part of this Lab Kit were available in the Virtual World Tour 2014 webinar […]

Live digital threats

I wanted to bring these free tools to my blog to keep track of them, as most probably I will forget about, and to share with anybody interested in gathering information in the security areas. First tool was revealed to my in tweet from Greg Ferro: Blog post: Response: Digital Attack Map http://t.co/rEhfYAN77c pic.twitter.com/0O1L6kELsK — […]

Cisco switches and smartport macros

Smartport macros are not more than some templates you can define on Cisco switches that will apply the same configuration on multiple ports. It’s not a subject that needs too many discussions, but it can be useful for your Cisco certification preparation or real life Cisco switch administration. Configuration is very simple and it goes […]

Cisco STP forward-time command trick

This is more a topic for exams, like Cisco CCIE, but also it can appear in real-world environments. Consider the following simple topology: SW1 is the spanning-tree root bridge for all VLANs. Imagine that you have a request which ask you that when a port becomes active, no matter of VLAN, it should wait 10 […]

EtherChannel over 802.1q Tunneling

Consider the following topology: We have one Customer with two distributed locations (SW1, R1 and SW2, R2) connected over Provider backbone. What we want to create is something like this: If Provider support 802.1q and L2 tunneling we can achieve a nice Etherchannel between our 2 remote locations with direct CDP visibility. Also STP and […]

Ubuntu OVF images for download

Lately I’m playing a lot with virtualization features and for this I needed a rapid way to deploy from scratch new instances. First I had the virtual machines converted to templates, but then I had to rebuild from zero the entire ESXi environment and those images were gone. I realized then it was more easier […]

MAC address tracking with NMS

Let’s assume that I have a port open in my Cisco switch for guest users and I would like to keep track of the new mac-addresses that are added or existing mac-addresses that are removed from that port. I have a NMS (Network Management System), capable of receiving SNMP, traps that will send me an […]
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