One of the things that took me a while to get was how to edit an ACL after I had configured it. I used to just copy/paste the ACL from the running config into notepad, make my edits, then delete it out of the router, then paste it back in. Sometimes that’s still the fastest way if you have lots of changes- but for the little stuff knowing how to edit and resequence is helpful. Here’s a quick guide:
There are basically three ways to prefer one equal cost route over another in EIGRP. All three either change the metric (modify delay or the composite metric), or change the administrative distance.
On the CCIE lab, we may have to configure a DHCP server. Here’s a quick configuration, as well as a few helpful commands for doing that quickly and easily.
As I get closer to my lab date there’s a number of things I want to make sure I remember. At the top of that list are things that save me time, suffering and typing. Here’s a list of my favorite alias commands that I seem to have to type all the time:
Last time, I went over layer 2 diagramming- here’s how I diagram the layer 3 Internal Gateway Protocols (IGPs).
One of the most helpful tools for getting things to work in the RS CCIE lab is being able to quickly put together a drawing that has the information you need. Since the lab is now all digital (no more workbooks), it’s helpful to have a document you can look at and write on. The proctor will provide you with two pieces of paper, and colored pencils. Here’s how I set up a layer two diagram.
There are books on BGP, and to say it’s a huge topic is an understatement. Anyway, here’s some of the most helpful commands I’ve found for figuring out what’s going on with BGP routing and neighbor relationships.
show ip bgp [prefix]
- shows route info in BGP table. Will show no best path if route is not synchronized. Will show inaccessible if the next hop is not available. Will also show dampened routes.
R707#show ip bgp 146.16.0.0 255.255.252.0
BGP routing table entry for 146.16.0.0/22, version 23
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Multipath: iBGP
Flag: 0x820
Advertised to update-groups:
1
1 6, (aggregated by 6 188.112.1.8)
188.112.1.16 from 188.112.1.16 (10.10.0.1)
Origin IGP, localpref 100, valid, external, atomic-aggregate, best
Cisco likes to do a lot of manual configuration of frame relay on the Routing and Switching CCIE lab. Here’s some debug commands and their output to remember.
The following must match to become neighbors:
Here are some notes to remember and commands for debugging EIGRP:
In my previous post on CCIE Lab Equipment, I talked a bit about alternatives for your hands on rack time. I listed the pros and cons on why I decided to go with rack rentals versus buying. I certainly can’t find fault with buying your own equipment if you have the funds, power, and space- so for those rats who are thinking about furnishing their own lab, I thought I’d do some digging on the 3550 versus the 3560. As I write this 3550s are going for about $200 on eBay.
Every protocol has a specific command to manually summarize routes. Some of them have multiple ways depending on what type of route you are summarizing. Here’s a brief list of how that works.
Once you’ve completed your CCIE lab foundation study for the CCIE lab, it’s time to pull the trigger and get good with the equipment. I worked with three vendors and a variety of training methods during my lab preparation- I’ll give you a little detail on each and then make a recommendation on how I would have done it if I had to start over again.
According to Cisco, here’s the CCIE R&S (4.0) equipment.
When it comes to priority, there’s not a whole lot of consistency across the routing and switching domains. As a good general rule, you can remember “Layer two, lower priority, layer 3, higher priority.” Of course BGP messes with that with the attributes, but in a pinch it helps.
For identical routes advertised from different protocols, the default behavior of the router is to use the lowest administrative distance. The administrative distances (AD) are:
Shockingly, sometimes RIP doesn’t just work when you set it up. Especially when you’re working with a time constraint, and under stress, like on the CCIE lab. Here’s a few tools to debug RIP and figure out what’s going on.
Many times in CCIE lab preparation (and production, of course) you have to backup and restore configurations to routers and switches. It’s easy- here’s the commands.
It’s very common to use a terminal server to aggregate console connections to router and switch racks. Here’s a quick reference on the commands for their use- this works with any Cisco terminal server- such as CCBootcamp’s or GradedLabs rentals.
OSPF authentication must be declared with TWO statements. Either one areawide statement under router configuration to activate authentication, and an interface statement, or two statements under the interface.
In the last note we talked about subnetting. Sometimes instead of breaking network into smaller chunks, we have to go the other way and summarize. To do this quickly in decimal, we have to do a bit of work using powers of 2. It’s pretty similar to the old CCNA days when you needed to figure out how many hosts or networks were available in each subnet mask.
Wendall Odom taught me subnetting after I just couldn’t get it for years. A subnet mask is just a filter to show which bits belong to the network, and which belong to the host. When I first learned to subnet I did it in binary, which was slow and painful. This method uses decimal (mostly, you have to know a bit of binary to get the correct decimal mask value). Here’s how it works
BGP
neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
Route Switch Lab Tips is NOT a CCIE study guide. It’s a collection of tips and tricks I have picked up along the way toward the exam. It’s helpful as you are getting to your final preparation. Before that, it’s important you have a SOLID foundation before you attempt the lab. I spent the last year studying, earning my CCENT, CCNA, CCNP and passing the the CCIE written. I’ve read a ton of books (about 8 feet worth- yes, I stacked them up), sat through more than a few bootcamps, and if I had to start over again, this is how I would do it.
Hello and welcome. Route Switch Lab Tips is basically my study notes for the Cisco CCIE Routing and Switching Lab. It’s a collection of time saving tips and tricks to help prepare for this difficult and challenging exam. Look around, and if you have any feedback let me know through the contact page.