Root Bridge Election Results What command can I use right now assuming both of these are Cisco switches to see what ports are connected which ports? Answer: show cdp neighbor What else should I run here if I’m checking connectivity between these two switches over this crossover cable? Answer: That’s called a trunk. So we
Whether we’re layer 2 or Layer 3 and (that’s core switching at Layer 2 & routing at layer 3), we love redundancy. We’ve got to have a backup path, because a single point of failure for anything in today’s networks it’s just not acceptable. (A “single point of failure” is a point in the network
(The Link Layer Discovery Protocol) For every Cisco-proprietary protocol or service, there is an industry standard, an equivalent service that can be run on non-Cisco devices. For CDP, that industry standard is the Link Layer Discovery Protocol (LLDP). LLDP is going to give you information on directly connected devices. They don’t have to be directly
You’re just giving someone a banner of information at a certain time when they are connecting to a router. Now we’re going to create three different kinds of banners here. We’re going to create a log in, a message of the day, and an exec banner… and really the only difference is where they appear
The Cisco Discovery Protocol (CDP) is super-helpful in the right circumstances. We’ve used it here and there to view info about directly connected Cisco devices, and we’re using it again now to see which Cisco devices are directly connected to this Cisco switch. Let’s go ahead though and bring our switch back up and we
To this point, I’ve disabled timestamps to make the various log messages easier to read. SO at the top of the config you used to see this : In real-world networking, they’ll almost always be on, so we’ll get the timestamp service up and running (and maybe peek at another service or two) before we
The thing with logging is that the defaults are so good that you rarely adjust them! There are three main methods of accessing log messages, and it won’t surprise you to find out the commands for each are just a bit different: Again the defaults are so good but you might have times when you
what I will do is remove the static route that we have on router 2 right now. And we want to see a fully specified route in action We’ve seen the first two of our three regular types where we have recursive which is going to specify the next hop IP address and then directly
As we were suspecting, R2 cannot ping R4. They are on different subnets and version 6 is advanced but not that advanced! So we have to add a little something here… Typically in a network we could and likely would configure OSPF, RIP, or EIGRP for IPv6, but we’re saving those for another IPv6 section.
We’re going to send some v6 pings from R2 to R3 over their shared subnet, then from R3 to R4 over their shared subnet, and we’ll see first off what’s going on there before we try any end to end pinging. There are really three different ways to send pings with IPv6. The first one