Cisco 1941 ISR router teardown an detailed overview for CCNA lab and repair

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Cisco 1941 ISR router teardown an detailed overview for CCNA lab and repair

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8 жыл бұрын

Complete tear-down and overview of a Cisco 1941 ISR G2 series router, which are real good devices for small businesses and for being used at a branch office site.
In the video I try to answer the question whether this is a good router for CCNA candidates and small businesses.
In the first portion of the video the hardware and the motherboard is being analyzed in detail from the point of view of a CCNA certification.
In the second portion I make a 10X magnification of the components, and explain their functionality for component-level repair technicians.
Sorry for the dark video, but in spite of 6000 Lumen of light my
Canon Rebel T3i DSLR makes worse movies than a potato.
Parts list for the Mainboard discussed in the video:
====================================
Main Processor: Cavium Octeon Plus CN5220
Physical IO chip for Layer1: Marvell 88E114-NNC1 Gigabit PHY
FPGA: Xilinx Spartan XC3S200A
RAM: 512MB DDR2 RAM
NVRAM: 24C02H (2Kbit EEPROM)
ROMMON: 25P40VP 4Mbit Flash
Flash: Cisco 512MB compact flash card
Serial Console: ADM2209 RS232 transceiver
Real-Time-Clock: DS1337C
Parts list for the components:
====================================
U3M LT6105?
U4M RC1K=LMV321
U3F 24C02H
U200PS 17-9330 Custom or rebrand
U1M 17-9329 Custom or rebrand
U1Q AB12818 (no datasheet)
U26P MIC5209MY
U1K DS1337C
U2K Pericom P16LC4831AZBIE (no datasheet)
U1J NXP VC2244A
U6C Texas Instruments 385B25
3.3V to 2.5V: 2* LDDW221 in parallel
U117E=U116E=U115E IDT Q534X245Q3G (PCIe Switch?)
U15W Marvell 98DX-LKJ1 (no datasheet)
U3T Zarlink ZL30110
U3I 25P40VP 4Mbit Flash
U1I Xilinx Spartan XC3S200A
U1F Spansion S99-50283 Flash (no datasheet)
U1N=U7C=U1J VC2244A
U1U Micrel 2026 USB power controller
U7CN CY7C64215-28PVXC USB controller
U1G0=U1G1 Marvell 88E114-NNC1
U6CN ADM2209EARUZ
U2A0 Texas Instruments LC08A
U11P BZN T1 2929 Linear regulator (no datasheet?)
RAM Samsung K4T1G1604F 1Gbit DDR2

Пікірлер: 43

@yvettelaudat9546 5 жыл бұрын

Mr. Don Key, you keep it real. I am referring to your opinion on buying this router. Here is my scenario. I was doing a CCNA Security Lab with three 2800 routers and 2 3750 switches. This lab is called Securing the Router for Administrative Access. The commands stopped working on page 29. For example: cryptographic-algorithm hmac-sha-256. I tried the original ios and changing out my ios to a security ios and that did not work. I bought 3x 1941 routers so I could do these labs. My routers have a security package on them. Tonight the first problem that I ran into is that one router boots into rommon mode. It has its compact flash missing and the black tab is sticking out. I am currently trying to work out this situation so I can run my lab..........I found a solution on KZfaq: Recover Cisco Router using tftpdnld command_rommon. My result after trying this is: TFTP: Error, insufficient flash installed to load image. TFTP: Operation terminated.

@DonkeyLearningIT 5 жыл бұрын

Yeah, the Cisco 1900 series routers are pretty good, plus they are running IOS 15, which is almost a must have for labs above CCNA/CCNP. Also for small companies it is a good router to purchase as well. When it comes to your problem, I would say that you have physically unplugged the flash card from the slot. Can you check whether the flash card is in the slot, and whether the flash card is well seated? I would unplug it and plug it back in first, just to make sure that it is well seated in the slot.

@yvettelaudat9546 5 жыл бұрын

@@DonkeyLearningIT Hi. Thank you for responding. The metal lid on compact flash slot 0 is gone. There is no flash card in the slot and the black ejector tab is sticking out. I can see green inside this slot. These 1941 routers are from Ebay. The other two routers aren't missing anything and they boot up normally.

@DonkeyLearningIT 5 жыл бұрын

@@yvettelaudat9546 OK, so that clearly means, that you will have to get a flash card, and also somehow an IOS image. Eventually you could try to plug a flash card from one of the working routers into the third one. Though, when it comes to IOS features, I am not sure what happens with the feature keys, since with the new licensing system it is more tricky. Just putting on the IOS is not enough to get full functionality, you might hat to purchase the keys from Cisco.

@exxr 8 жыл бұрын

back to the cpu, it seems Cisco (and also Juniper, who uses these Octeons in their SRX) don't fully make use of the hardware accelerated ASIC-type features present in this chip. the only company that appears to make full use is ubiquiti with their edgerouter series. these devices like ER-lite and ER-8 use the cavium offload features for IPv4/6 forwarding, firewall, VLAN, PPPoE and of course IPSEC making them blisteringly fast for their size. just about the only thing they don't have offload support for is QoS.

@DonkeyLearningIT 8 жыл бұрын

Btw, this multi-gigabit fabric (MGF) is than somewhat similar to DMA, so the CPU is not doing interrupt handling? However, if it is bypassing the CPU, how are they still able to guarantee security? I mean if there is some evil code in the RAM being injected, that might do very nasty things, or when the CPU is initiating the DMA transfer, it first checks for such things?

@exxr 8 жыл бұрын

+Donkey Learning IT The MGF is basically a Gigabit switch. See www.cisco.com/c/en/us/td/docs/routers/access/interfaces/software/feature/guide/mgfcfg.html#wp1054087

@yvettelaudat9546 5 жыл бұрын

Hi. I got the last response. The guy who i bought it from on ebay us helping me with it. I am about to carry the router to a Best Buy and get help with it. I will get the compact flash and help opening the cf slot. Can't open it.

Жыл бұрын

Thank you for very imformative video.

@yvettelaudat9546 5 жыл бұрын

Hi. I just came from best buy. They only sell cf cards 32G and higher. The max my router takes (Cisco spec sheet for 1941) is 4G. Also went to Walmart and they don't have it.

@DonkeyLearningIT 5 жыл бұрын

Naah, for Cisco equipment you would need to buy a Cisco CF card. Other third party cards might work, but I mostly had problem with those. You should be able to buy the Cisco cards used off Ebay for relatively cheap. Though, as I wrote, the issue is that you would need to buy the software keys from Cisco, which might be really expensive for a lab.

@mattwilson1669 5 жыл бұрын

Thanks Don, very informative. What RAM module fits into the DIMM slot? What is the max sized RAM that can be used?

@DonkeyLearningIT 4 жыл бұрын

I would only buy Cisco RAM module which is sold particularly for this model. To be honest with you, personally I have never installed a RAM upgrade in the 1941 series, and I rather not give wrong information.

@morlock9216 3 жыл бұрын

Gentlemen, what kind of RAM (1Gb or 2Gb) can be installed in this router? Plain non-ECC unbuffered? And what is the frequency: PC2-5300 or PC2-6400?

@user-sr7fo5fe6x 3 жыл бұрын

I'm also trying to find out. But I believe its ECC (non-F) (non-buffered). Look for the E on the end. 2GIG max.

@robertxiong1603 8 жыл бұрын

Hey again! How do you know what chip does what? I'm very interested to know how you know! For example @14:37, how do you know that's NVRAM and not something else? Did you work for cisco?

@DonkeyLearningIT 8 жыл бұрын

+Robert Xiong Hi Robert. I wish I would have worked for Cisco. The brain of a Cisco design engineer runs orders of magnitude faster than mine (at least that is what I think based on the designs they come up with). If you like IT, and you have passion for IT equipment, after one repairs a couple of units, one just knows already where to look, and how to read quickly the board layout and the datasheets. This is how you just look at a chip, and you know that if it is a small EEPROM with a size below 0.5MB, most probably it is the NVRAM. If it is a block-write chip (i.e. small flash) with a size between 1-2MB, than it is most probably the ROMMON. When you bump into rebranded chips and Cisco specific chips, than you can only guess what their functionality is. That little bit of knowlegde I have was gained by wasting my time at a university (which I regret), and luckily also working as a repair guy to finance my studies in the IT fields related to my "studies". I really mean it, the university was USELESS. It was a total waste of time and money, because todays education system is completely broken and decoupled of reality. All you get is a sheet of paper, and a bank account with lots of depth on it. If I would have not worked in small companies during my studies, I have not gained any real applied skills or knowledge. This is why I tell young people NOT to spend their precios time and get themselves into depth for a useless sheet of paper. Certifications and skills are more important. If they want to get a university degree, they can do it later once they have experince, and they actually know what they want to study and do in life.

@andromedaworld2970 5 жыл бұрын

how to disable onboard memory if any memory chip is faulty so that use slot memory to make it working

@DonkeyLearningIT 5 жыл бұрын

I am not sure about that. In fact, it seems that the chipset will initialize the onboard memory first, which makes sense. Eventually if you have somebody with good skills and decent equipment, they might be able to replace the memory for you.

@ZaxMan3D 5 жыл бұрын

Hi, Im considering getting a 1941 for home use, and im looking in to ways there i can mod it for a better cooling (less noice) i see you dont remove smaller heatsink, can it be replaced, or is it epoxy glued on?

@DonkeyLearningIT 5 жыл бұрын

I would *not really* buy an 1941 for home use except if you can place it into a basement where you do not hear it. These routers produce lots of noise and heat, and even modding it will not improve much with the heat. Do you really need the futures and throughput of an 1941, or you can get away with a smaller router? If your answer is yes, and you would be bothered by noise, go for a different router.

Жыл бұрын

How can i contact you bro? Can i ask different question?

@vikaspotadar 3 жыл бұрын

What are recommended router for homelab??

@solaimankhan9996 4 жыл бұрын

Cisco 1941 ISR router Power Supply repair video require

@yvettelaudat9546 5 жыл бұрын

The guy at best buy opened the cf slot for me. I put the cf card from the good router into the bad router. (The router that was booting into rommon) This is the message I got: This is what I am seeing on my screen currently: *Jan 5 19:42:41.575: %SMC-2-BAD_ID_HW: Failed Identification Test in 0/-1/-1 [7/0] The module in 0/-1/-1 in this router may not be a genuine Cisco product. Cisco warranties and support programs only apply to genuine Cisco products. If Cisco determines that your insertion of non-Cisco memory, WIC cards, AIM cards, Network Modules, SPA cards, GBICs or other modules into a Cisco product is the cause of a support issue, Cisco may deny support under your warranty or under a Cisco support program such as SmartNet. *Jan 5 19:42:56.815: %FILESYS-5-CF: System CompactFlash 0 removed *Jan 5 19:43:41.575: %SMC-2-BAD_ID_HW: Failed Identification Test in 0/-1/-1 [7/0] The message kept coming back. We thought my vwic3 card might not be an authentic Cisco product. I moved my vwic3 card over from EHWIC0 to EHWIC1 and still got the same message referring to the same slot. He thought it might be the PVDM card. I didn't put one in so this gentleman is sending me another router on Monday.

@anilemailsharma 7 жыл бұрын

How to disable onboard memory on cisco 1941

@DonkeyLearningIT 7 жыл бұрын

As far as I know the onboard memory is always used since it is mapped by the chipset to be the base RAM where the ROMMON is being decompressed. Thus, I would say that you cannot turn it off, but I might be of course wrong.

@stevenhulme1332 6 жыл бұрын

Hi.How can I contact you. I repair Cisco equipment everyday and would like to ask 1 question. Thanks

@DonkeyLearningIT 6 жыл бұрын

Just send me a mail, no problem. Hopefully I will be able to give you some useful comments. You will find my mail on the channel details page.

@jamesorlindabbay4195 5 жыл бұрын

Can i input GLC-SX-MM to this router?

@DonkeyLearningIT 5 жыл бұрын

Sorry for the late reply, I was moving to a new place. When it comes to GLC-SX-MM, I do not know this card, and I do not want to give you the wrong information. However, you should be able to ask your Cisco vendor whether you can put this card into the router, and they will help you out.

@EveryDayLifeChannel9777 7 жыл бұрын

A lab is for people who've never seen a router and switch in person and are not mechanically inclined. Save your money and practice on packet tracer!

@DonkeyLearningIT 7 жыл бұрын

I agree that one can learn most things related to the software from PacketTracer. However, knowing the hardware is highly important since ultimately it is what runs the software. More importantly, when someone is hired for a job, they must be able to take care of both the hardware and the software. In fact, the software part is getting so smart, that SDN (software defined networking) will soon take over. Here in the EU we have large companies which have not even a CCNP on their premises, and they never had to punch in a command into a Cisco CLI because they went full SDN. However, cabling, screwing things into a rack and plugging things into routers&switches&servers will not be replaced by robots for decades to come...

@EveryDayLifeChannel9777 7 жыл бұрын

True but for someone who's use to taking things apart and putting them back together it's elementary.

@DonkeyLearningIT 7 жыл бұрын

That is indeed true, you are totally right! Actually the reason I like to make these videos is that I hope that I can give some insight to those people who cannot afford to build themselves a lab (when I was younger, I was totally broke). Plus I also learn new things by making these videos.

@jamalkhan815 6 жыл бұрын

Practical hands own experience counts in real world, also the Packet Tracer is just a simulation software which is limited and not all the commands are supported in Packet Tracer

@DonkeyLearningIT 6 жыл бұрын

That is my personal opinion as well. In a job *real hand-on experience* matters. Although it is easy to pick up the skills on the hardware front, for most job interviews it can be a complete deal-breaker, because the people interviewing you might think that you know nothing about the equipment...

@vardanik88 7 жыл бұрын

If you want to see what inside cisco 1941, view this video kzfaq.info/get/bejne/qNKbjNqJs9HVg2w.html

@DonkeyLearningIT 7 жыл бұрын

Mean no offense for the person who made the video, but what is the point of a video without explanation? What is the message? Classical music playing, and all I can see is a guy with a screwdriver. He might be 100x better expert than I am, but still... The image/sound and production quality of my own videos are total trash. However, I actually give some information which provides a bit of value for people to watch/learn from it.