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Need Help with Surfboard 5100 Modem

Will a Surfboard 5100 server as a router? It has a DHCP server built in, but two computers connected through a switch are not able to get IP addresses. I read somewhere that the Surfboard is not really a router unless the cable is down. The one machine that is work is pulling a public IP. The other machine is not able to get an IP address ("server unreachable.")

At one point, the cable was, in fact, down, and the working machine pulled a private IP address.

What's going on with this unit?

Thanks!

Reply to
mcp6453
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I just tried an experiment. I connected both my Linux firewall and notebook computers, to my modem via a hub. When the modem is off line, both computers can get an address from it and communicate. However, shortly after switching the modem back on line, the notebook loses it's address and the firewall reverts to it's original address.

Reply to
James Knott

As I mentioned, I have a firewall I built myself, using Linux. In addition to the ethernet ports for the local network and wan, I've also got another nic for my wifi, a vpn and dial in access. You won't find many cheap firewall/router boxes that do all that.

Reply to
James Knott

The 5100 is not a router. It will, however, act as a DHCP server, and assign IP addresses when there is no active coax connection. You may need to release and renew the IP on a machine connected to the cablemodem to be served an address.

Make sure that you are releasing and renewing for the correct adapter. If, for example, you have an internal dial-up modem installed, renewing all connections will also attempt to renew a lease via the dial-up adapter (PPP adapter) and you'll receive a server unreachable error. Release/renew only the Ethernet adapter's connection.

The IP addresses served by the cablemodem will be 192.168.100.11,

192.168.100.12, etc.
Reply to
Warren

Yep, if you buy more ip addresses from rogers.com both would run on the cable modem. Or buy a router not a hub and you can run both through the single ip address.

Reply to
Bit Twister

Agree, I also run linux as my firewall box and do not have to worry about a virus disabling the firewall. :)

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Reply to
Bit Twister

The SB5100 comes with a standby switch, that disconnects the local side, from the internet. It might be a good idea for Windows users to make use of it.

Reply to
James Knott

Yes, that standby switch is a very good firewall. 8-)

But average time for an windows infection is 16 minutes after connecting to the net with a new box. That is quicker than downloading the updates. For new virues they have to wait for an AV vendor to catch the virus, test the detection/cleanup, load into the production database, and sometime later the customer loads the update to stop the malware. :(

Reply to
Bit Twister

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