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The vPC technology is configured between two and only two Nexus switches. Catalyst switches provide no vPC functionality. The switches bound together in the vPC setting are called vPC peer switches . Unlike other stacking technologies like VSS, Nexus switches in a vPC configuration do not form a single control plane; they maintain their own control plane, and share a common control plane between them. That is why we can ssh into each Nexus switch seperately, while that is not possible in a VSS setup. vPC peer switches are linked together using at least 2*10Gbps links, configured in a port-channel. These links form what is called the vPC peer link . vPC peer switches maintain also what is called a vPC keepalive link. This is NOT a physical link, but rather a logical link that runs across the vPC peer link. Nexus switches in a vPC setup must be configured with something called a vPC domain . two vPC peer switches must have the same vPC domain value. vPC peer switches are taken from this...

LLDP Show commands are easy to understand. Cisco IOS images that support LLDP Read the section Cisco IOU Unsupported Features . LLDP configuration on Cisco devices DLS-1#sh lldp neigh % LLDP is not enabled DLS-1# DLS-1# LLDP show commands on Cisco devices DLS-1#show lldp neighborsCapability codes:(R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device(W) WLAN Access Point, (P) Repeater, (S) Station, (O) OtherDevice ID Local Intf Hold-time Capability Port IDTotal entries displayed: 0DLS-1# Give it some time to gather information about neighbors and re-run the command. DLS-1#show lldp neighborsCapability codes:(R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device(W) WLAN Access Point, (P) Repeater, (S) Station, (O) OtherDevice ID Local Intf Hold-time Capability Port IDTotal entries displayed: 0 DLS-1#DLS-1#DLS-1#DLS-1#show lldp neighborsCapability codes:(R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device(W) WLAN Access Point, (P) Repeater, (S) Station, (O) Othe...

Using Vmware Workstation is a nice tool to practice Cisco technologies. And sometimes you encounter errors that drives you nuts such as “The specified virtual disk needs repair” error message. This error could occur for example when you brutally shut down a virtual machine. But no worries, there is a solution. If you are running a Windows host machine, run a Windows command line and type this command: vmware-vdiskmanager -R “{path of the vmdk virtual disk}” In my case, here is how I solved the problem: d:\Program Files (x86)\Vmware>vmware-vdiskmanager -R "D:\Virtual Machines\ISE 2.0\ise2.0-000001.vmdk"The virtual disk, 'D:\Virtual Machines\ISE 2.0\ise2.0-000001.vmdk', was corrupted and has been successfully repaired.

In this article I am going to lay the important facts for doing a Cisco ISE upgrade, from version 2.0 to 2.1. These recommendations are also valid for other upgrade versions. My tools are: Vmware Workstation Pro 12 Cisco ISE 2.0.x virtual appliance software, as initial version Cisco ISE 2.1 upgrade patch ise-upgradebundle-2.0.x-to-2.1.0.474.SPA.x86_64.tar.gz 3Cdeamon TFTP server I used at first Filezilla FTP server. It sucks. The download process hangs and freezes often. I spent a whole sunday afternoon figuring what the problem could be. I switched to using the manual CLI command to copy the upgrad bundle from an FTP server. I got errors during the copy process too. By the way, when you use FTP as your copy process, the FTP server must be already declared as a repository in CLI in ISE, and the CLI command is: copy ftp://192.168.1.254/ise-upgradebundle-2.0.x-to-2.1.0.474.SPA.x86_64.tar.gz disk:\ this simply did not work on my lab. then found this link and followed the instructions: htt...

Here is my experience with the Cisco CCNP exams and the material I’ve used to study and pass them. First, make sure to download the official exam blueprints and read them carefully. Here is a quick link to the CCNP Routing and Switching syllabus in PDF format, as of May 4th, 2015. Before we jump on the topic, let us look at the prices of the CCNP exams: Implementing Cisco IP Routing (ROUTE) 300-101 : exam costs about 200$ Implementing Cisco IP Switched Networks (SWITCH) 300-115 : exam costs about 200$ Troubleshooting and Maintaining Cisco IP Networks (TSHOOT) 300-135 : exam costs about 150$ If you book one of the exams, you may find that in your country these prices are a bit different, even after currency conversion. That was the case for me, with every Cisco exam. The testing center I deal with buys Cisco exams from Pearson Vue Europe (in Euros). It charges its own fees, in addition to the high conversion rate from Euro to Tunisian Dinar. So each Cisco exam costs me about one th...

Eve-ng is probably the most notorious competitor of GNS3. I discovered it by accident. I am collecting below all my ramblings. Installing EVE-NG Here is what you’re going to need, in order to setup a EVE-NG home lab: OVA file EVE-NG client side software. I use a Windows machine so I downloaded the Windows client side. Vmware Workstation, preferably Workstation Pro Filezilla FTP client: will be used to transfer binary files into EVE-NG The following resources are useful: Link1 Linke2 and of course the EVE-NG project homepage Running Kali Linux with EVE-NG There are two ways to run Kali Linux on EVE-NG: running a liveCD version installing the full image of Kali I’ve tried both. I thought of running a VM version of Kali, which was the most stable option in my lab. Running Kali as a standalone VM and networking it with EVE-ng was not difficult. The VM image is already available free to download here . I added the VM as a template and connected it in Bridged mode with a ...

In this article we focus on the configuration of Cisco IP SLA in three flavours: ICMP-echo, ICMP Jitter and delay. Configuration steps The quick steps to configure IP SLA on a Cisco device are: – create the IP SLA monitor – configure it – schedule it Cisco IOS did not show me help when I type interrogation mark. Yet, commands are accepted. IP SLA Track Delay IP SLA delay is an option that facilitates the failover and fallback of links when you have multiple of them. A common complaint among network engineers is that a primary link flaps up and down, and with it flaps the secondary links too. In order to avoid flapping back and forth between the primary and the secondary links, and assuming there is IP SLA configuration with tracking (see a sample configuration for IP SLA tracking applied to Policy-based Routing ), you can tell the IOS to wait a certain delay before declaring an tracked object officially down or up. Cisco IP SLA delay configuration The delay command is ...