Re: Unable to log on a Cisco G300 switch.

LaurentARNOUX6889 · ‎07-23-2019

Hi all,

I've just moved to an house where a G300 switch is behind a router provided by the internet provider.
the former owner left without giving me proper information so I need to explore the network from scratch.

the router is acting as DHCP provider and deliver adresses in the 192.168.1.X range.

I'm perfectly able to log and configure this router and I see that there is something with the appropriate mac@ connected. Meaning, the low layers sound correct.

When connected to this router, the switch has his system light flashing. I understand that it means that it's using it's default IP@ 192.168.1.254.

But there is no reply to pings on that adress and I'm unable to log on the switch from a browser.

With nothing else connected to the switch but the router, I used a sniffer (Angry IP scanner).
This sniffer has detected the router on 192.168.1.1 but nothing else.

Note that everytime I've tested something, I did the test connecting the router to the port #1 of the switch but also connecting the router to one of the Gbit port of the switch (#49). Don't know what is most appropriate but results were the same.

I tried to connect my laptop to the console port using a DB9- RJ45 cable. No lights on my laptop RJ45 port and nothing happened.

Connecting my laptop to the switch as standalone (not connected to the router) with RJ45 cable, my latptop receives a 169.254.29.20 Address. It seems that it's a kind of default address, not meaning that the switch delivers DHCP address in that range nor that he has it's own adress in that range.

Then I finally tried to factory-reset the switch.
putting a trombone and then a pin in the reset hole during 20s (even longer, I think I've waited for a minute), but the switch didn't reset.
I think that when the reset is acknoledged, all switch ports are flashing, no ? this never happened.

So, I'm out of idea, and will appreciate any help.
I'm a software engineer, so I have notion of networking but pls if you can help me, appreciate if you can be as explicit as you can and consider you are talking to a rookie.

Also note that my english is what it is... not so bad but mayday mayday when reaching technical discussion.

Thanks to the community.

Laurent.

kubn2 · ‎07-23-2019

@LaurentARNOUX6889 wrote:

I tried to connect my laptop to the console port using a DB9- RJ45 cable. No lights on my laptop RJ45 port and nothing happened.

Hi,

~~Well first after plugged console cable in did you tried open it via Putty or other program that can use "console connections"?~~ I don't have SG300 but I expect it via console cable you will have CLI not gui interface in web browser.

First of all you using wrong cable. DB9 to Rj45 its not normal rj45 which will communicate with PC you need rj45 serial port. If you have it then try putty but I guess you don't have it so best chocie would be (rs232)db9 to usb.

Connecting my laptop to the switch as standalone (not connected to the router) with RJ45 cable, my latptop receives a 169.254.29.20 Address. It seems that it's a kind of default address, not meaning that the switch delivers DHCP address in that range nor that he has it's own adress in that range.

It's APIPA address assigned by OS by it self if it cannot connect to DHCP so you can ignore that no DHCP running on this switch.

I would try again with factory reset maybe you didn't press this hidden button strong enough and it didn't reset it?

pieterh · ‎07-23-2019

When the device is using the factory default IP address of 192.168.1.254, its power LED flashes continuously. When the device is using a DHCP-assigned IP address or an administrator-configured static IP address, the power LED is on solid.

-> should indicatie that you are correct, a flashing light means the switch has it's default ip-address

If the device does not receive a DHCPv4 response in 60 seconds, it continues to send DHCPDISCOVER queries, and adopts the default IPv4 address: 192.168.1.254/24

-> in addition to above this could mean the switch does not get an ip-adress in time from the router at 192.168.1.1

.,....my latptop receives a 169.254.29.20 Address.

-> yes this means your pc cannot contact a dhcp-server and generates it's own address (APIPA = automated private IP address)

-> manually configure your PC with an 192.168.1.x address and try if you can connect to 192.168.1.254

LaurentARNOUX6889 · ‎07-23-2019

Thks Pieter,
Anything I can do to extend the timeout for the switch to receive an address ?

LaurentARNOUX6889 · ‎07-23-2019

Thanks for your help Kub

I agree that with the console port, I'm supposed to use an hyperterminal or a putty tool.

However, since I've seen no light on my RJ45 plug of my laptop, I guessed it won't work.
and by the way, searhing the device manager of my laptop, I've seen no COM port created once the cable was pluged-in.

Maybe I'm using the wrong cable. Any amazon reference I can purchase ? something that you are sure will be the right cable ?

on the factory reset, I've tried several time, each time even harder & longer.
Is it possible to lock this factory reset button ?
Anything I can do from inside If I open the machine (I don't care if this break the warranty or the switch itself)

BEst regards

L.

pieterh · ‎07-24-2019

to speed up dhcp negotiation you need to configure the switch first :-(

the console port (marked blue) is a serial connection.

[edit: ~~you connect the cisco blue RJ45/db9 ccable with the rj45 side tot the switch~~

the switch has a db9-console port, you may need an extra serial cross cable to connect ]

and the db9 connector to

- a pc with integrated serial port with db9-connector

- or a db9-usb serial-converter

NOT the rj45-connector in your computer!

alternatively you connect a, ethernet rj45-rj45 cable from a network-port on the switch to the netwerkport on your computer

and manually configure an ip address in the same subnet as the default address of the switch

LaurentARNOUX6889 · ‎07-26-2019

Pieter,

"alternatively you connect a, ethernet rj45-rj45 cable from a network-port on the switch to the netwerkport on your computer

and manually configure an ip address in the same subnet as the default address of the switch"

I've tried.
pluged on the switch (any port) My laptop receives a @ip in the same subnet mask 192.168.1.X.
But again, trying to ping 192.168.1.254 which is supposed to be the @ip of the switch (system led flashing), returns nothing.

pieterh · ‎07-28-2019

If you have a windows pc do a "ipconfig /all" to see what dhcp- server gave you that ip address

if this is not a third device than this is the ip-address of your switch

if it is a third device (your internet router), than ignore the system led flashing.

login into that dhcp server to check if it did hand out an dhcp-address to your switch