I love when tools make my life easier. A conversation came up online the other night and I had shown someone a quick summary of the awesome power of Sublime Text. They wanted to know how I made the magic happen in that video. I felt I should and share it with everyone via a blog post. Here’s a quick video of my uses along with a description of what you can do with it, as well as how to make it work.
Config-ease with Sublime Text Snippets
Permanent link to this article: https://www.packetpilot.com/config-ease-with-sublime-text-snippets/
Bulk enable PIM via TCL
I’ve been working on doing some multicast labs lately and am constantly resetting my lab devices to their default configs and starting from scratch. As many of us know, to enable PIM on all of your interfaces you must go into each interface and enable it manually. There is no default command to enable PIM on all interfaces. We know PIM should be enabled 1 to 1 with interfaces involved in routing making this a boon. With that in mind, and the fact that I am rather comfortable with the concept of needing PIM on the interfaces, and likely speak and type this command in my sleep, I decided to make it easier and modify a previous TCL script I had written to enable PIM on every interface that has an IP address assigned to it. With the great “Send to Chat” feature of SecureCRT I can do this across my entire topology on one fell swoop. In a real world environment, you could use a tool like Solarwinds to push this out to your devices.
Permanent link to this article: https://www.packetpilot.com/bulk-enable-pim-via-tcl/
Apps for a Network Engineer Part 1: MAC
MAC for Network Engineers
I am not going to play bias in anyway towards any particular apps. I’m surely not going to get into the debate between Windows or Apple as a primary computer. In fact, I’ve spent the last 4 years using Windows exclusively for work due to work issued laptops and the lack of support for Mac in the companies I have worked with. However, I recently purchased a new Mac to get back to what I personally like best, with that, I had to rebuild my app repetoir for doing my job on a Macbook. This took some digging and searching to find apps similar to what I used on Windows. I’m still searching for all the app alternatives but I figured I could make this into a working document of my favorite apps in terms of network engineering.
Permanent link to this article: https://www.packetpilot.com/apps-for-a-network-engineer-part-1-mac/
Automated IP Communicator Launch against Multiple Clusters
If you manage multiple CUCM clusters you are likely to have Cisco’s IP Communicator installed on your computer. Cisco IP Communicator is a software based phone installed on your computer that connects up to CUCM and lets you utilize your PC as if it’s a Cisco desk phone. This is a pivotal tool to quickly move a phone between different call managers. I recently fell into this demographic while working on a migration/collapse of multiple CUCM clusters. A lot of time was spent in the GUI of IP Communicator changing TFTP Server address (let alone trying to remember them all). I took a couple of hours and figured out what would be needed to automate this task via a batch script with a simple menu based script. The details are found below.
To start, I found that the TFTP servers were stored in the registry. However, these TFTP servers were not in standard IP address form. They were actually stored in Hex, but the octets were rolled over while keeping the bits in the standard left to right order. The process to create the correct value’s for the registry is as follows.
Permanent link to this article: https://www.packetpilot.com/automated-ip-communicator-launch-against-multiple-clusters/
Tracked Static Default Route
As common place in today’s networks redundancy is key. Applications are the key components to business obtaining revenue. More and more applications are becoming SaaS and ecommerce is here to stay. With that being said, many companies are moving to redundant connections to the internet. These connections could be through two different ISPs, or both connections to the same ISP. Often times these connections will be of different speeds to save on costs. The key to these connections is to maintain internet connectivity.
Permanent link to this article: https://www.packetpilot.com/tracked-static-default-route/
Cisco OSPF MD5 Authentication
Continuing with our OSPF and interior gateway protocols we will not look at an MD5 implementation utilizing OSPF on a Cisco router. We will again continue with our 3 router topology as used in both the EIGRP MD5 example and the OSPF plain text example. There are very few changes that will need to be made to our earlier OSPF example using plain text. The topology is as follows.
Permanent link to this article: https://www.packetpilot.com/cisco-ospf-md5-authentication/
Cisco OSPF Plain Text Authentication
Continuing with our interior routing protocol discussion on authentication we are going to look at Cisco OSPF implementation of plain text authentication. While this isn’t the most widely used model for authentation with OSPF it is a viable option. The topology we are going to use is the same topology from the EIGRP authentication example. The steps may feel familiar as well.
Permanent link to this article: https://www.packetpilot.com/cisco-ospf-plain-text-authentication/
Overlapped IP Range in a Merger
The Scenario is this…Company A has purchased Company B. One is an enterprise of thousands of users, the other a mid size company in the multiple hundres. However, as would happen to be the case, both companies utilize an overlapping subnet. To further complicate the issue it has been decided that both companies need to terminate at Company A’s core and utilize a single unified instance of EIGRP. As part of this scenario, both companies need to be abble to access each others networks but luckily it has been determined that neither need to be able to access each others overlapped networks. Additionally both companies advertise different bit masks on their overlapping networks. This is something that we can work with.
The following examples show the additional configuration required for the specific scenario above. The full router configurations are posted at the end of the article.
Permanent link to this article: https://www.packetpilot.com/overlapped-ip-range-in-a-merger/
Router on a Stick
The scenario looks like this. You’ve got a branch office with a single router connecting to your corporate office over the WAN. In your branch office you have a single layer 2 switch and a desire to separate traffic into multiple broadcast domains. Maybe you want an easy way to allow only HR computers to connect to a very specific branch office server and the only place for any restriction of traffic is on that branch office router. Here is where your router on a stick comes into play.
Permanent link to this article: https://www.packetpilot.com/router-on-a-stick/
Static Routing with Cisco
Routing is at the core of the network infrastructure. Routing is what ultimately lets you get from point A to point B not only in your own network, but also across the entirety of the world wide web. Routing in its simplest form tells your network devices the path to get to another network device located on another network. This was originally handled by creating static routes to the required destinations.
Permanent link to this article: https://www.packetpilot.com/static-routing-with-cisco/