Help making CCNA lab!

[TheGeeker]

I am planning on having my lab kit with:

 

1x 2811 Router at 73 USD

1x 2821 Router at 79 USD

 

2x CIsco 2960 WS-C2960-24TC-L V10

1x CIsco 3560 L3 Router Do I need one these or just three 2960s?

[brwainer]

10 minutes ago, TheGeeker said:

CIsco 2960 WS-C2930-24TC-L V10

a 2960 or a 2930?

[TheGeeker]

Just now, brwainer said:

a 2960 or a 2930?

2960 SOrry

[brwainer]

Just now, TheGeeker said:

2960 SOrry

np, just helping make sure it's clear. Also, do you need both a 2811 and a 2821? or is it just because you need two routers for testing configurations between each other, and want them to be different models?

[TheGeeker]

Just now, brwainer said:

np, just helping make sure it's clear. Also, do you need both a 2811 and a 2821? or is it just because you need two routers for testing configurations between each other, and want them to be different models?

Well, I think I will need two routers for the lab and my house's Internet is faster than 10/100 so I was going to use the 2821 as it has gigabit ports

[brwainer]

2 minutes ago, TheGeeker said:

Well, I think I will need two routers for the lab and my house's Internet is faster than 10/100 so I was going to use the 2821 as it has gigabit ports

I looked for a specification for routing capacity, but I could only find this as an official document, which talks about switching speed. I figure that any routed traffic also has to be switched, so the switch limit should be a hard cap on routing as well. https://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf the 2821 has a fast/cef limit of 86Mbps

 

This forum has a person saying the routing limit is 87Mb/s - so I think my assumption was correct: https://supportforums.cisco.com/discussion/10777776/2821-throughput-isp

[Riddler356]

Ok, i just spent 15min googling, and what the heck is a CCNA/CCNP Lab, all i can find is people making them, cisco selling them, and others talking about what makes a good one or a bad one. but all i want to know now is what is it, and what do they even do/are for.

[brwainer]

Just now, Riddler356 said:

Ok, i just spent 15min googling, and what the heck is a CCNA/CCNP Lab, all i can find is people making them, cisco selling them, and others talking about what makes a good one or a bad one. but all i want to know now is what is it, and what do they even do/are for.

CCNA and CCNP are cisco certifications. A CCNA lab is just a set of hardware that you use to study for the certification tests

[TheGeeker]

7 minutes ago, brwainer said:

I looked for a specification for routing capacity, but I could only find this as an official document, which talks about switching speed. I figure that any routed traffic also has to be switched, so the switch limit should be a hard cap on routing as well. https://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf the 2821 has a fast/cef limit of 86Mbps

 

This forum has a person saying the routing limit is 87Mb/s - so I think my assumption was correct: https://supportforums.cisco.com/discussion/10777776/2821-throughput-isp

So the 2821 will not provide gig speeds? I am connecting it to a sg-300 28 port.

[brwainer]

1 minute ago, TheGeeker said:

So the 2821 will not provide gig speeds? I am connecting it to a sg-300 28 port.

the ports may link at gigabit speeds, but using it as a router with NAT will not even give you 100Mb speeds.

[TheGeeker]

2 minutes ago, brwainer said:

the ports may link at gigabit speeds, but using it as a router with NAT will not even give you 100Mb speeds.

Ok. Is there a difference with the 2851?

[brwainer]

Just now, TheGeeker said:

Ok. Is there a difference with the 2851?

the 2851 can do 112Mbps - https://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf

[TheGeeker]

1 minute ago, brwainer said:

the 2851 can do 112Mbps - https://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf

So I should get a 2811 and a 2851? Also do I need the 3560 L3 switch?

[brwainer]

Just now, TheGeeker said:

So I should get a 2811 and a 2851? Also do I need the 3560 L3 switch?

I've never made a CCNA lab, and I've only barely started studying for it. I'm not in a position to make a recommendation for what you should get. But I do recommend that you don't plan on having your main router for you house also be something you use in your lab.

[TheGeeker]

2 minutes ago, brwainer said:

I've never made a CCNA lab, and I've only barely started studying for it. I'm not in a position to make a recommendation for what you should get. But I do recommend that you don't plan on having your main router for you house also be something you use in your lab.

Is it possible to have it part of the network though? 

[brwainer]

Just now, TheGeeker said:

Is it possible to have it part of the network though? 

I'm not sure what you mean. you can do anything with your lab that you want - I think most people connect their labs to their main network except when they work on things that intentionally cause loops. But I would not recommend that any of your lab equipment be responsible for the connection to your ISP. The point of a lab is to be able to make mistakes and learn safely.

[leadeater]

You would make the 3560 the core of your network and do all the inter-VLAN routing on that and then create a /29 or /30 link between the 3560 and the 2811/2821/2851 etc for the actual internet connection. This way you only need the routers to be faster than the internet connection and any limitations of internal networking won't be an issue.

 

[leadeater]

Also speaking from experience having your lab network be your actual day to day network is rather annoying, linking them is fine but it is rather tiresome losing access to everything if you want to do a major reconfiguration. 

[legopc]

Personally I would get 1x 3560 and 2x 2960 and for routers its dependent on your budget, personally I would just get 3x 2821's, but 2811 will also do just fine. 

[Lurick]

Why buy physical hardware when you can easily virtualize it all these days for less. I would look into something like VIRL and Packet to do all of that for you and it will easily get you through the CCIE even.

[U.Ho]

22 hours ago, brwainer said:

I looked for a specification for routing capacity, but I could only find this as an official document, which talks about switching speed. I figure that any routed traffic also has to be switched, so the switch limit should be a hard cap on routing as well. https://www.cisco.com/web/partners/downloads/765/tools/quickreference/routerperformance.pdf the 2821 has a fast/cef limit of 86Mbps

 

This forum has a person saying the routing limit is 87Mb/s - so I think my assumption was correct: https://supportforums.cisco.com/discussion/10777776/2821-throughput-isp

This is not entirely accurate and should not be used as is to measure switching speed.

 

Switching speed varies with packet size and that router performance sheet you linked states that switching capacity calculation is done using the pps value and multipliers so that it represents 64B packets. So that's the "minimum maximum speed" it's capable of if you crank your packet size all the way to minimum. 

[U.Ho]

A feasible packet size would be somewhere between 1000 and 1400 bytes.

Calculating with the same formula as the Cisco paper, that's over 1Gbps with 1000 and way more with 1400.

 

Edit:

Oh, the formula: "Mbps calculated by pps * 64bytes * 8bits/byte"

Find it on page one of the pdf, last paragraph before table 1.

[brwainer]

2 hours ago, U.Ho said:

This is not entirely accurate and should not be used as is to measure switching speed.

 

Switching speed varies with packet size and that router performance sheet you linked states that switching capacity calculation is done using the pps value and multipliers so that it represents 64B packets. So that's the "minimum maximum speed" it's capable of if you crank your packet size all the way to minimum. 

 

1 hour ago, U.Ho said:

A feasible packet size would be somewhere between 1000 and 1400 bytes.

Calculating with the same formula as the Cisco paper, that's over 1Gbps with 1000 and way more with 1400.

 

Edit:

Oh, the formula: "Mbps calculated by pps * 64bytes * 8bits/byte"

Find it on page one of the pdf, last paragraph before table 1.

While this is true, these were the only numbers I could find for this router - there were no other specifications that I could find, whereas for modern routers you can usually find RFC2544 numbers.

[Brightglaive]

23 hours ago, leadeater said:

Also speaking from experience having your lab network be your actual day to day network is rather annoying, linking them is fine but it is rather tiresome losing access to everything if you want to do a major reconfiguration. 

Speaking as one that has both set up CCNA lab equipment and exercises on physical equipment AND taught CCNA classes, having the equipment is satisfying and comforting and wonderfully tactile. Easy to put hands on, have physical connectivity, and try to resolve physical connection and cabling issues locally. However, you don't often get that luxury as a network admin. You have to get used to configuring and troubleshooting remotely. That's the reason why GNS3 (or VIRL and Packet) is so handy. Quick reconfigurations are easy and integration with physical hardware is possible as well. 

2 hours ago, U.Ho said:

This is not entirely accurate and should not be used as is to measure switching speed.

 

Switching speed varies with packet size and that router performance sheet you linked states that switching capacity calculation is done using the pps value and multipliers so that it represents 64B packets. So that's the "minimum maximum speed" it's capable of if you crank your packet size all the way to minimum. 

As the packet size goes up so does the throughput. But the PPS goes down. There is a maximum throughput and PPS of mixed packet sizes but it's not generally advertised. Oh and yes the throughput does rise above the maximum listed on that sheet at higher packet sizes.

 

Keep in mind that the first packet in any stream is process switched and all subsequent packets are CEF-Switched. Process switching is like searching for a person in a phonebook by starting with the first entry in the list and seeing if its the correct one then moving to the next if it's not. Binary searching is also used to cut the each search by halves. 

 

CEF switching is like looking alphabetically. It searches by octet and each subsequent octet. So it will search for the first number. For an IP address of 175.230.64.110. It will look for the first number (0-255) and then under 175 it will search again (0-255) then under 175.230  and so on until its find the final octet which has the actual location of the route in the routing table (If I recall correctly it actually lists the interface/IP address to send the ip packet from/to). As you can imagine this is much faster than to search a routing table for an entry 1-by-1. However on a router this is all done in IOS software. 

 

On a switch this is done by a specialized hardware processor called an ASIC. Because it's done in hardware L3-switching can reach into the millions of packets-per-second and hundreds of Mbps on up into gigabits per second. 

 

 

[leadeater]

3 minutes ago, Brightglaive said:

Speaking as one that has both set up CCNA lab equipment and exercises on physical equipment AND taught CCNA classes, having the equipment is satisfying and comforting and wonderfully tactile. Easy to put hands on, have physical connectivity, and try to resolve physical connection and cabling issues locally. However, you don't often get that luxury as a network admin. You have to get used to configuring and troubleshooting remotely. That's the reason why GNS3 (or VIRL and Packet) is so handy. Quick reconfigurations are easy and integration with physical hardware is possible as well. 

Quite true, I did most of my study on virtual equipment with tests done on physical equipment. It's also a heck of a lot quicker to setup network scenarios in a virtual lab than it is in a physical lab.

 

My CCNA is super old and lapsed, not in a networking role and haven't kept the certification up to date. I'm a Systems Engineer and focus on integration of systems which by nature includes networking, firewalls and virtual networking but for the first two I work with the dedicated teams that are responsible for those areas. I consider myself very good in the core fundamentals of networking but I'm sure as heck no expert and lack the higher end certifications and training.

 

P.S. As a side note my lab actually has nothing to do with CCNA or specific network training and encompasses multiple physical hosts (across sites), hardware firewalls, currently rather basic switching (looking for 10G upgrade options) and diverse ISP connections from different providers. Hence the reason why if I make any major changes I'm not functional till I'm finished but that's usually no more than a few hours, but premise still stands it can get annoying if you get lazy and want to take a break and your internet is down and your steam library is hosted on an inaccessible VM.