Solved: SRW2024 console unconnectable / unknown "switch ip"

Hareide85 · ‎12-16-2009

Model No: SRW2024 ver. 1.1

Serial No: RIE1061000687 GGR2806 MM

Namelesstag: 0014bf59A19E

Bootup sequence:
Time: 0s - Power cable inserted
Time: 0.1s - System led glow / Fan starts
Time: 2s - Port status leds glows for connected devices (since my router and laptop has gigabit, "Link/act" and "Gigabit" leds glows (green/yellow)

I bought this switch on ebay. The seller said that he had just jused it to "split up the internet".
He had never used it as anything else then a standard switch. He didnt have the "ip" of the switch or the username/password for administrating it.

I know that you can easy log into the switch through the console despite "not knowing the password".

The switch works like a standard "non-managable" switch. All ports work, and I can connect a TP-cable from my router to the switch, and one from the switch to my computer. This works for all ports.

But im unable to reach the switch configuration. Web dosnt work, since i dont know the ip of the switch. I have tried some kommon ip's like 192.168.1.1/192.168.1.254 and 10.0.0.1/10.0.0.254 with no luck.

Normally this wouldnt be a problem, as you could connect through the serial console port (rs-232).

I can't connect through the console port.
I have a usb-to-rs232 converter that I tried without luck. This converter has worked for simular devices in the past (dreambox, other computer), but I dont get any response from the switch when using windows hyperterminal.

Thinking the serial cabel might be bad it made me try he "loopback test". By shortning pin 2-3 on the "switch side" of the cable. Now I get the characters i type in the hyperterminal, and this tells me that the this isnt a cable issue? Or could it stil be?

Settings used:
Com: 27
Bits per second: 38400
Data bits: 8
Parity: None
Stop bits: 1
Flow Control: None

I thought this might be because "usb-to-rs232" converters dosnt always works. I hooked up my old celeron computer, with windows XP. It has one serial communication port, but it failed to give results.

I also tried to connect the serial cable to my laptop and my old computer. This works. Characters typed on one computer appears on the other computer.

Can I use the "74-0495-01" to anything (picture below)? It was in the box with the switch, but as far as I know it isnt usable on this switch.

Questions:

Is it possible to "deaktivate" the console port? That gives me a slight chance to find the "switch ip".

Is there any way to restore the switch's default configuration by shorting something inside the switch? Then i could connect to the default ip: 192.168.1.254
Is it odd that the switch works when it seems like the switch configuration side seems to be dead?

Does anyone else have some other thoughts or tips?

jzelcans · ‎12-17-2009

Hi Hareide,

Here are a few things that come in my mind:

1. Check if you are using straight through DB9 - DB9 cable, not crossover

2. Try to use lower baud rates in hyperterminal, in case the speed has been changed. The common rates are 2400, 4800, 9600, 19200

3. You can install Wireshark software (http://www.wireshark.org/) on your computer and capture traffic from the interface connected to the switch. You may see the IP address of the switch in some packets, or if it's requesting an IP address by DHCP. In the second scenario, you will need to plug the switch to a network with DHCP, to allow it to pick an address and then access it by web menu/telnet

Let us know if this helps you,

Best Regards,

Janis

View solution in original post

jzelcans · ‎12-17-2009

Hi Hareide,

Here are a few things that come in my mind:

1. Check if you are using straight through DB9 - DB9 cable, not crossover

2. Try to use lower baud rates in hyperterminal, in case the speed has been changed. The common rates are 2400, 4800, 9600, 19200

3. You can install Wireshark software (http://www.wireshark.org/) on your computer and capture traffic from the interface connected to the switch. You may see the IP address of the switch in some packets, or if it's requesting an IP address by DHCP. In the second scenario, you will need to plug the switch to a network with DHCP, to allow it to pick an address and then access it by web menu/telnet

Let us know if this helps you,

Best Regards,

Janis

Hareide85 · ‎12-17-2009

I have a noname nullmodem cabel. Shop link

I have checked the wireing with a ohm-meter. The wireing is like this:

1 -> 7

2 -> 3

3 -> 2

4 -> 6 + 8

5 -> 5

6 -> 4

7 -> 1

8 -> 4 + 6

9 -> 9

As 2 and 3 are "crossed", does this mean that my cable is a crossover?

Hareide85 · ‎12-17-2009

1. Check if you are using straight through DB9 - DB9 cable, not crossover

This was spot on!

In a srw2024 manual it said:

"1. Power off your computer and Switch.

2. Connect the provided null modem cable from the COM port on your computer to the Console port on the Switch"

This is wrong and you where right. The switch dosn't use a null modem cabel, but a "straight through". Therefore my null modem cabel didn't work. I made my own cabel and kept it simple: TXD, RXD, GRD

Pinout:

2 <-> 2

3 <-> 3

5 <-> 5

And it worked. Tank you for the help. I was starting to loose hope!

SRW2024 console unconnectable / unknown "switch ip"

Cisco Business Product Family

Cisco Switching Product Family