I'm not familiar with Summit switches (I have tried Cisco switches)

So if your switch has Console port (usually they need either serial cable or RJ45)

Im gonna assume it's RJ45. Your RJ45 cable ends with serial end just like in this picture:

You plug the RJ45 into the switch. The other end needs to go to your computer. If you're computer has serial port input, great.. If not, then you will need a good quality serial to USB cable.

Go to your device manager on your computer and find out what COM number you have.

Take a look at my attachment.

In my computer it's COM9, open putty and follow the attachment picture.

Answer from tuxy on Stack Exchange
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US Converters
usconverters.com › downloads › support › db9_rj45_assembeling_guide.pdf pdf
www.usconverters.com Making a DB to RJ45 adapter.
The astute will note we have a potential disaster here. Let's say we clip the wire from RJ45 pin 1 as close · to the DB9 pin as possible, strip it a bit, then wrap it around the DB9 pin connected to RJ45 pin 2.
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Digi International
digi.com › support › knowledge-base › using-an-rj45-adapter-to-connect-to-a-db9-connecto
Using an RJ45 Adapter to Connect to a DB9 Connector | Digi International
January 1, 2024 - Select your product for firmware, drivers, software, knowledge base articles and manuals · An example application for these adapters would be to extend the RS232 serial connection so that the radio modem might be located closer to the antenna location so that the antenna cable will be as short ...
Discussions

How to connect to a Summit switch via PuTTy using a RJ45-DB9 cable - Network Engineering Stack Exchange
I have the following: Windows 7 Putty .66 RJ45-DB9 I have been out of the networking field for quite sometime (10 years) and I forgot how to console into a switch. Do I need to configure my PC More on networkengineering.stackexchange.com
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Confused about proper pinout with an RJ45 to DB9 adapter
The device has a control box that accepts RJ45 cable. I am sending my commands via a Global Cache iTach WF2SL device which has a DB9 serial port. I am attempting to connect the two devices using a Cat-6 T-568B cable, and a RJ45 to DB9 adapter. The WF2SL pinout uses 2 - RX, 3 - TX, and 5 - Ground. More on community.spiceworks.com
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DB9 to RJ45 serial connect to switch - correct pinout?
This pinout worked for me: RJ45 -> DB9 RTS 1 -> 8 CTS DTR 2 -> 6 DSR TXD 3 -> 2 RXD GND 4 -> 5 GND GND 5 -> 5 GND RXD 6 -> 3 TXD DSR 7 -> 4 DTR CTS 8 -> 7 RTS IIRC, I had to leave one of the ground pins unplugged. http://i.imgur.com/O3RRKQC.jpg *Edit: Here's another picture for clarity. Also, you can push the pins back out with something like a small flathead screwdriver (~1mm). http://i.imgur.com/7hWniXb.jpg More on reddit.com
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July 27, 2017
serial - Can't figure out EIA-232 (RJ45) to DB9 cable... (seems simple!) - Electrical Engineering Stack Exchange
The front of the unit has an RJ45 port (EIA-232) and has a wiring diagram on how to wire it to a DB9 port so you can connect it to a PC. More on electronics.stackexchange.com
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December 22, 2012
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Instructables
instructables.com › circuits › computers
Simple RJ45 DB9 Cisco Console Cable : 4 Steps - Instructables
November 5, 2017 - Simple RJ45 DB9 Cisco Console Cable: Hello everyone, I just bought my first cisco router (2610) and, in order to learn about it I decide to start a blog. The idea its to provide a step-by-step from nothing to something that can be useful in a SOHO environment. The blog still in the …
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Juniper Networks
juniper.net › documentation › us › en › hardware › mx2020 › srx4600 › topics › concept › port-rj45-db9-adapter-pinout.html
RJ-45 to DB-9 Serial Port Adapter Pinout Information | Juniper Networks
The console port on a Juniper Networks device is an RS-232 serial interface that uses an RJ-45 connector to connect to a management device such as a laptop or a desktop PC. If your laptop or desktop PC does not have a DB-9 plug connector pin and you want to connect your laptop or desktop PC ...
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YouTube
youtube.com › backyard tech
Connecting an RJ45 serial to DB9 com port - YouTube
Continuing with viewer request on console access to V120 sun server, this is how to connect RJ45 serial to DB9 serial com port. Link you using console: https...
Published   March 4, 2017
Views   17K
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Schempal
schempal.com › home › how to wire db9 to rj45: a detailed diagram and step-by-step guide
How to Wire Db9 to Rj45: A Detailed Diagram and Step-by-Step Guide
November 18, 2023 - Learn how to wire a DB9 to RJ45 adapter with this detailed wiring diagram. Connect your devices with ease using the correct pinouts.
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Details Pin
detailspin.com › home › pinout rs232 db9 to rj45
RS232 DB9 to RJ45 Pinout: How to Connect and Use
June 16, 2024 - One key element in this process is understanding the pinout configurations of different connectors, such as DB9 and RJ45. This article aims to provide a comprehensive overview of the basics of DB9 to RJ45 pinout, highlighting the importance of proper pin connections and the role they play in establishing reliable communication.
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CocoonTech
cocoontech.com › home › forums › general › wiring closet
Need DB9 to RJ45 Help | CocoonTech.com
March 25, 2010 - So one batch might have the orange wire on pin #1 of the RJ-45 connector and another patch might have the orange wire on pin #2. So if you only look at a sheet you created that says orange should always be pin #3 of your DB-9 connector, if the colors are swapped on the RJ-45 you will pull your hair out in frustration wondering why it doesn't work. BTW - I'm bald now...... Click to expand... I completely agree. I whipped out the multimeter and put it on it's audible ohm setting to figure out what the existing configuration was on the cisco db9->rj45 adapter.
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Snap One
snapav.com › shop › en › snapav › binary-trade-db9-male-to-rj45-modular-adapter
Wirepath™ DB9 Male to RJ45 Modular Adapter
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Rotel
rotel.com › faq › what-pin-configuration-db9-rj45-cable-required-use-rs232-port-or-upgrade-software
What is the pin configuration for the DB9 to RJ45 cable required to use the RS232 port or upgrade software? | Rotel
June 20, 2020 - The rear panel of many Rotel models ... the internal software in the unit. A special RJ45 to DB9 conversion cable is required in order to connect from a standard DB9 serial connection....
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Update

As I originally predicted, the wiring is proprietary and the flow control signals are a mess. @SofaKng has reversed engineered the official cable and produced this table (reproduced here):

RJ45 pin,   DB9 pin (female)
----------------------------
  1           1
  2           6 + 8
  3           2
  4           5
  5           5
  6           3
  7           4
  8           7

Original

You missed a key detail. Their RJ-45 patch cable is null modem wired. That means it is reversed. You got all of your pairs backwards (you connected TX to TX, RX to RX, etc...)

Assuming you are using a straight-through patch cable...

  • as you indicated that you are with your comment "standard TIA-568B"
  • you must use TIA-568B ordering on both ends of your patch cable

...it goes this way:

Device Signal, RJ-45 Pin#, DB9 Pin#, PC Signal
----------------------------------------------
> DTR 1 --- 6 DSR   
> GND 2 --- 5 GND
> RTS 3 --- 8 CTS
> TxD 4 --- 2 RXD
> RxD 5 --- 3 TXD
> DSR 6 --- 4 DTR
> GND 7 --- 5 GND <-- note: repeats, bussed to device #2
> CTS 8 --- 7 RTS
> RI  9 --- 9 RI  <-- doesn't actually fit in an RJ-45 (only 8 signals), probably safe to ignore if I read their diagram correctly

The DB9 on a PC is pinned out this way (see figure). Note how it is null-modem reversed from the table listing you provided. That's because their RJ-45 cable is null-modem reversed to cancel it out. Tricky and silly, but that's how they chose to implement it.

Some other thoughts...

Actually, I noticed from tracing in the diagram that they do some very strange stuff with the flow-control signals. For example, they short CTS and DSR on the PC side, but not on the other side. They route RTS on the PC side to DSR on the device side. And other weirdness.

This may be bad documentation, but I suspect they have implemented custom firmware/software that makes use of the flow-control signals in non-standard ways as a means of ensuring that you only buy and use their cables and adapters.

I would suggest that you make two half cables. On one end go RJ-45 to unterminated wire and the other go DB9F to unterminated wire. Then you can twist your way through all of these weird configurations until you get it right. I would start with my suggested mapping. If that doesn't work, report back and I'll give you my mapping for all of their weirdness in the flow-control lines.

Good luck! =)

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I ended up ordering a premade cable and adapter from Pacific Custom Cables and they worked so I checked the pin-out of the RJ45 (null-modem) to DB9.

Based on their pin-out, I made a new cable (crimped RJ45 on one end, soldered DB9 female on the other end) and here is the working pin-out:

RJ45 pin,   DB9 pin (female)
----------------------------
  1           1
  2           6 + 8
  3           2
  4           5
  5           5
  6           3
  7           4
  8           7

I don't understand why that is the pin-out but that's what works and the pin-out from "official" cables and adapter.

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Eaton
tripplite.eaton.com › products catalog › network adapters › p44089ff
DB9 to RJ45 Modular Serial Adapter, RS-232 - Tripp Lite - Eaton
The adapter features a female DB9 serial connector with color-coded twisted-pair wires on one side and an RJ45 female connector on the other, allowing you to create customized RS-232, RS-422 and RS-485 connections.