Welcome back, everyone. So in multi layer switching, but now we're going to talk about Seth. All right, Seth was originally created Cisco Express forwarding for routers writing for higher performance. All right, four to four packets, all right, using dynamic lookup tables. Now one of the tables that we will look at is the fit, we'll get into that a little bit. Stuff also has been carried out or to the catalyst switch platforms just to make things a lot quicker.
A lot quicker goes with that 40 information base. It does take a look at certain things to make things faster, sort of runs by default. All right, taking advantage of those specialized hardware, so not all, that kind of switches, some habit. They don't have the full capabilities. Some do depending on what airline cards you have, but we'll talk about that in a second as well. Oops.
Okay. Now the writing table is reformatting enormous with the most specific raw first for each IP destination subnet table, we know this, we take a look at it, it will look at the longest prefix. Because when we talk about prefix we're talking about subnet mask. So the subnet mask with meaning longest to utilize the device with ultimately five there'll be the longest mask, the longest prefix, you know, 24 to the two, and so forth. Okay, so it's ordered in that way. The new format is called fed 40 information base forwarding information base that contains routing and forwarding information that the network prefix can reference.
That field will have the information even before the routing table will that's why I can make quicker decisions and send it on its way. The third will contain more specific subnets. Again, longest match first, followed by the less specific subnets Alright, so it's doing more or less the same thing in the routing table. It's just going to do a lot quicker. And I'll probably have it right before the routing table will. The footballs will contain that next layer three Hubbard dress was The routing table does not.
So it'll look at the next hop address that where to send the information to or the router it takes a while because of the has to get the the updates from the next router and so forth. The fav also contains the router the most efficient routing logo directly connected close or adjacent pose rarely found in routing tables. Okay so it has a lot more information it does a lot more than the routing table. So that's why I Sef is great and routers is not on by default, you can turn it on IP Sef there it is, it's on or ipv6 if you can turn it on on the routers or on the switches is already on by default. Again, depending on the type of switch you have, it may take four um it will take the full capacity of everything, take advantage of it for manager of that particular card.
If it's possible, if not then use about get another inline card so I can go ahead and take full advantage of it. I bought the Definitely is one of the tables get created with F, that's going to make your packet forwarding a lot quicker. All right now the Fed is dynamic, it builds itself, any changes to the topology, routing, whatever the Fed will get updated. You can display the Fed table using what show IP SFX. Right, it will show you all everything that that particular table has. You show IP Sef with a particular network, I look at this network with the longer prefixes or I'll take a look at this network in detail.
So it will give you information about that particular network the path to everything. All right now after the after the fit was built, we'll use the path in the Fed to for information. If we go if not enough information exists, it will be some back to the layer three engine to say hey, listen, I don't have enough information to gather it up in North ascend that word needs to go so it will Go ahead and send them back. But when enabling stuff, this is the 40 information base, this is the table that gets built, which is awesome they go is going to be is makes life a whole lot easier, makes your network much more efficient. That's why an MPLS and MPLS. When we talk about packet or Label Switching, actually Label Switching the fame is the routing table.
The four is the routing table for MPLS. forwarding information base, obviously with MPLS is based on labels here, we're not talking about labels at all. Okay, and finally, there's two types of stuffs Okay, there's the accelerated stuff distributed across multiple layer 348 is typically located on the individual line cars, the chassis based catalyst switches, these engines This is where I was telling you, these animals do not have the capacity to store and use the entire food The individual line cars in chassis based catalyst switches, they don't have that. Okay, but every using these f catalyst 6500 has line cards that support these F, each with its own table so you'll be able to easily each card has its own fit table, it will take full advantage of that 40 information base. What are we saying with this particular lecture? Man you stuff.
Take advantage of as if it's not on check if it's on. If it's not on, turn it on IP Sef that, definitely create that third table, make sure that your cars will be full advantage of it. And your network should be running a lot smoother with it. You should enabling your routers as well, not just because you're not running MPLS or what have you, is just creating that table. That's gonna have more information than the routing table. Especially About your neighbors that doesn't have to wait for updates.
It gathers our information and sends the packets to frames quickly out. Okay, that is that in the next one