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Q: Home Networking Issue with Switch

DarkWolffeI have an Allied Telesyn 10/100Mbps Fast Ethernet Switch. Plugged in is the main line to port one, direct from my Comcast router, an IBM ThinkCentre 8143-28U to port two, an Xbox 360 "classic" (mfr date 2009) in port three, and a custom built with a Gigabyte Z77-DH3 board into port four. Now, the...

networking ethernet switch
Everett
Everett
Is the computer in question (the box on port 4) providing DHCP services? Is the computer (port 4 again) connecting through the Comcast router using PPPoE? If it is your Comcast account may be handing configuration information to the custom build, which then serves the other devices. What MAY be going on here is that the Comcast box is just acting as a media converter.
DarkWolffe
DarkWolffe
I don't believe it is, no, to either question. Networking isn't really my forte. I can tell you that the IP of the custom is *.4 where the others are *.6 and *.5
Everett
Everett
On the think center on port 2 if you do an ipconfig /all at the command line (assuming Windows) does the gateway address show up as *.4? In *nix based installs you would do ifconfig.
DarkWolffe
DarkWolffe
Yes it does, regardless of the custom. It does however display DNS errors when trying to view a page via Chrome when the custom is connected but powered down.
Sorry, no, it shows up as it should with *.5
Everett
Everett
I think I'm confused. The IP address of the ThinkCentre is *.5? What does it show as the Gateway IP address? Or if the ThinkCentre shows that the Gateway IP address is *.5, is that the IP address of the Comcast modem?
DarkWolffe
DarkWolffe
05:10
Okay. The modem is *.1, custom is *.4, IBM is *.5, and the Xbox is *.6. I also noticed that when the custom is off and I do a ipconfig /renew and ipconfig /release the IP address changes to 169.254.14.38, an IP I've seen when linking two computers directly via Ethernet cables without a network connection.
Everett
Everett
Could you possibly cut and paste the ipconfig /all output. What I need from the ThinkCentre is the IP address and the Gateway IP address.
Based off of what you just provided, when the Custom is off, the rest of the computers are using self assigned IP addresses. The Custom is assigning IP addresses to everyone (acting as a DHCP server). When it's off, the computers on your network know how to talk to each other (using self assigned IP's), but have no route out to the internet (the Custom is what provides it). The route to the internet is being provided by the Custom in the DHCP configuration.
This means that the Comcast box is likely just a media converter (broadband to baseband) taking the round cable, and changing it to an Ethernet connection. That is fed through the switch into the Custom that then uses PPPoE to create an Ethernet connection. Once it has done that, it hands out IP addresses to the computers on your network.
DarkWolffe
DarkWolffe
Any ideas on how to fix that? :/
Everett
Everett
It's not broken, it's working as designed. Remove the media converter, replace it with a router, and make the router create the connection OR if the media converter CAN act as a router, turn on that functionality, and stop your computer from doing it.
DarkWolffe
DarkWolffe
A media converter...?
Everett
Everett
I can't get more specific than that without knowing your equipment, reading directions... maybe call Comcast?
If you don't know what a media converter is (I've explained it twice in my answers so far (not being snarky, just pointing it out)) it would be like asking me to help you repair a busted head gasket when you don't know what an engine block is. AND we'd be doing it across the Internet, I can't see what your doing, and I don't know the make and model of your car... :)
DarkWolffe
DarkWolffe
05:10
I can give you the names and models of all the various parts, if need be. I can't say that I know what a media converter is, but I'm sure I don't have one.
The Internet goes from the wall via an RF line into the Comcast wireless router, where port one of that goes to the family computer (IP *.2) and port two to a small Dell desktop server I use for a small web host (IP *.3). The third port goes to the Ethernet switch's port one, which connects the IBM via port two (IP *.5), the Xbox via port three (IP *.6), and the custom via port four (IP *.4).
It's a complex system, but it's the only system available.

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