Jump to content

Welcome to Geeks to Go - Register now for FREE

Geeks To Go is a helpful hub, where thousands of volunteer geeks quickly serve friendly answers and support. Check out the forums and get free advice from the experts. Register now to gain access to all of our features, it's FREE and only takes one minute. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more.

Create Account How it Works

LAN fails with ISP outage

  • Please log in to reply



    New Member

  • Member
  • Pip
  • 1 posts



I work at a dental office and we experience frequent internet outages from our ISP(Comcast). We are using a Comcast modem/router which is connected to a 24 port unmanaged switch providing connectivity to our file server and workstations. We use a dental software(Dentrix) which stores a database on our file server, however, when we have an outage, we cannot access this data via our LAN connection. I'm not too familiar with networking, but is this because when the router is down, there is nothing assigning IP's to the computers? To fix this, can I configure our file server to act as a DHCP server when the router is down, so we still have LAN connectivity?


I'd greatly appreciate the help,



  • 0




    Trusted Helper

  • Malware Removal
  • 4,681 posts

Hi :welcome:



More than one DHCP server on the same network will give you troubles...


Why is the router down? even if the connection to the internet is down the router should provide IP addresses to the machines in your network and the local network should work!


One thing you need to do is confirm that your router can act as DNS server and cache (most do) and that the DHCP server configuration on the router is pointing the DNS server to the router IP in first place and second to the ISP DNS server or other public DNS server.


Many router DNS servers are not very fast, etc. but they should work fine for internals names and IP's, that is what you need to guarantee that the local network works without internet access.

  • 0

Similar Topics

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

As Featured On:

Microsoft Yahoo BBC MSN PC Magazine Washington Post HP