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New Member

Switch not sending dhcp discover messages to router

I have 6 Cisco SG200 switches on my network.  The three switches on the east side of the building are up and running fine with DHCP ( I know I know) but the three on the west side are all using the default IP address of  A month ago only two were using the default but the third lost power and had to be rebooted and cannot obtain DHCP.  I am very new to networking so I had some help in doing some packet captures on the router and know that the 3 switches are not sending a discover message to the router.  

A few weeks ago I set up the same model switch in another building and right out of the box with no configuration (with the exception of a 30 second reset hold) the switch got its DHCP and my connected access points are all in direct connect to the internet. I am trying to read up on what settings I need to adjust but I keep telling myself that it shouldn't be this hard.  It should be easy like the other switch setup.  

Is there something very simple I am overlooking (this is my vote since I'm a newbie) or did I somehow just get lucky with the last switch?  Currently the switch is completely default with no gateway.  

I just purchased a CCENT/CCNA book yesterday and I wish I had started teaching myself a few months earlier.  Any help would be greatly appreciated. 


I did notice yesterday that the firmware that the switch shipped with back in 2011 is still the present firmware.  Would out of date firmware be a suspect in this mess?

New Member

Are the switches with default

Are the switches with default configs ?

Is there a single DHCP server ? Is the DHCP on a router or other dedicated server is implemented ?

Is the scope available for dedicated subnet ?




New Member

I just started with the

I just started with the company a few weeks ago (first IT job) and the network was ran by an individual who was wearing many hats and could not contribute a great amount of time to networking.  All of the switches have default configs.  My first week here we powered up 2 other switches for another building and they came right up with DHCP.

A Meraki MX400 is running everything and is handing out DHCP.  

I just noticed that my subnet mask is a /30.  This network is 5 buildings with 12 switches.  I'm sorry, what do you mean by is the scope available for dedicated subnet?


If your MX400 is handing out

If your MX400 is handing out DHCP and your getting a /30 I would say you need to find out how it is configured to better understand the network design. If you have 5 buildings and 12 switches I would expect you have some VLAN setup somewhere! Are your switches are connected using trunk links etc etc.

I would certainly recommend getting static IP addresses on your switches outside of any DHCP scope so you know where they are when you need to manage them.