# how to access via CLI to a switch?



## wolffnx (Sep 18, 2020)

I read everywhere,including posts in here

the switch is a cisco sg350-28 and the adaptor is a serial to usb

when I use minicom appears the legeng "cannot open /dev/cuaU0!" , but if a restart the switch I see the boot in the screen

when I use  screen /dev/ttyU0 115200 , this takes me to a "menu" and when press enter takes me to "[screen is terminating]"

In the past posts I newer see a solution,anybody? help!


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## Mjölnir (Sep 18, 2020)

Add your user to the _dialer_ group `pw groupmod dialer -m wolffnx`, log out & in to apply the change.


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## kpedersen (Sep 18, 2020)

wolffnx said:


> but if a restart the switch I see the boot in the screen



This (and the "menu") sounds like you are able to read / write bytes but then it is dropping.
Could that be a baud issue?

Perhaps try changing the baud rate. I.e for screen:

```
screen /dev/ttyU0 115200
```

It seems like that device (or a similar model) can take a number of different baudrates:
https://community.cisco.com/t5/smal...ole-settings/m-p/2240250/highlight/true#M9108

Slightly further down in that thread someone suggested using 15200 baud and no flow control solved their issue.

so, something like:


```
screen /dev/ttyU0 15200,-ixon
```


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## wolffnx (Sep 18, 2020)

mjollnir said:


> Add your user to the _dialer_ group `pw groupmod dialer -m wolffnx`, log out & in to apply the change.


yes,I already do it


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## wolffnx (Sep 18, 2020)

kpedersen said:


> This (and the "menu") sounds like you are able to read / write bytes but then it is dropping.
> Could that be a baud issue?
> 
> Perhaps try changing the baud rate. I.e for screen:
> ...



thanks,I will try it


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## Mjölnir (Sep 19, 2020)

Usually you want to make shure you have 8-N-0 or 8-N-1.  Consult the switches manual and/or search Cisco related websites & forums


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