Here’s another short (but hopefully useful) post. We’ll be going through IOS Macros.
I’ve never used IOS Macros before, but I was asked about a problem today, and a macro seems to be an ideal solution. A friend of mine is an engineer for a service provider with a very large network. He has been tasked with implementing passive interfaces as the default for OSPF across the network. Most of the devices which will be modified rely on OSPF for management connectivity. When he runs the “passive-interface default” command, he will lose connectivity before he is able to run “no passive-interface [interface]” to restore connectivity. Macros tell the router to run the predetermined commands for us, which will save us from getting locked out.
The topology is simple and not worth a diagram. R1 and R2 are connected via their FastEthernet0/0 interfaces. They are running OSPF on this interface.
This is going to be a short post. I feel guilty for neglecting my blog (stupid ITIL), so I’m throwing this one together real quick.
There was a thread on Tech Exams recently, the poster was trying to figure out how to connect two subnets to a single Ethernet interface on a router. This was due to changing the address scheme within his company. Here’s what it looked like:
Very simple topology. The PC is part of the new address scheme and the printer is using a static IP from the old scheme. One of the easiest solutions here is to use a secondary IP on the Fa0/0 interface of R1. Here’s how it works:
EDGE(config)#int fa0/0 EDGE(config-if)#ip add 192.168.10.1 255.255.255.0 EDGE(config-if)#ip add 10.1.1.1 255.255.255.0 secondary
Very simple commands. Let’s verify:
interface FastEthernet0/0 ip address 10.1.1.1 255.255.255.0 secondary ip address 192.168.10.1 255.255.255.0
It worked, the interface now has two IPs. Now we would just configure the IPs on the hosts (or DHCP server) using the proper subnet and gateway. Once the hosts are configured, everything will work as desired.
As I explained awhile back, I’m working on the ITILv3 cert and haven’t really been digging into any Cisco/CCIE material. I’m not sure how much longer I’ll be at this ITIL stuff, but I really hate not posting. Without studying, I don’t have a ton of ideas for posts. I have one I’m doing later today on Secondary IP Addresses, but it’s short and simple.
Please post some article ideas in the comments section if you have any. Anything you guys would like to see, let me know. I can’t promise that I’ll do all of them immediately, but I will keep them on the backburner and post when I have time to throw something together or learn the topic well enough to get something decent up.
Greg at Etherealmind has created a petition for an educational IOS version. Details:
We the undersigned ask you to sign our petition.
We are the people who are learning about Data networking and Cisco IOS software. As students and practitioners, we need to learn theory and knowledge and then to take that knowledge and practice on Cisco IOS software.
We want to be able to practice that knowledge, and demonstrate our competence. We know that you are considering the value. This petition is to show our need for this solution. Wendel Odom discusses the possibility Cisco Considers IOS for Certifcation Self Study and we are calling for Cisco to make an option available.
This experience and knowledge we gain gives us the capability to make the most of Cisco equipment for our employers, your customers. We help drive the best return on investment, and keep the network performing in the way that your customers expect.
Sorry for the horrible lack of updates lately. I had to shift focus a bit to meet a job requirement. It’s come down from the top that everyone in the North American Network group within my company needs to get the ITILv3: Foundations cert by September of this year (ugh!). I’ve been cramming it like crazy and hope to knock the exam out in the next couple weeks. If that all works out I can get back to Cisco stuff and hopefully some decent posts.
If anyone is curious about ITIL, it’s terrible, lol. Supposedly it’s a valuable cert, so I can’t complain too much, but it’s just so boring. I love networking, so Cisco certs are actually fun for me. ITIL is just painful.
Anyway, check out my blogroll to get your networking fix.