Linux - NetworkingThis forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.
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I have been researching this issue for a few weeks now, and I have not found much luck. The most general problem is that the Debian system that I have newly installed will not connect to the internet after the initial installation. I have tried several fresh installs from different install images, and all have the same result: the system will connect during installation, but will fail to connect as soon as it does its first HD boot.
(On a side note, the same system previously ran Debian Sarge without any issue. No changes have been made to the NIC or any other system component. Furthermore, Lenny is installed as a fresh install. It is not an upgrade from Sarge.)
In addition to trying several installation images, I have also tried the following:
CONFIRMED THE NIC - I have confirmed that my LAN card is operational by using it successfully in other systems and swapping it for other cards that have also been proven on other systems. The cards are all CNet PRO200WL PCI Fast Ethernet Adapters and have been proven as Debian compatible on Sarge installations.
CONFIRMED THE PCI SLOT - I have run lspci and confirmed that they system recognizes the card. It recognizes the CNet PRO200WL PCI Fast Ethernet Adapter as "02:02.0 Ethernet controller: Davicom Semiconductor, Inc. 21x4x DEC-Tulip compatible 10/100 Ethernet (rev 31)"
CONFIRMED THE ROUTER AND CAT-5 CABLE - the CAT-5 has been swapped with other functional systems, and the router has assigned an IP address to the system dynamically (proving that a successful connection has occurred at least once). This IP assignment is viewed both in the Debian system and on the router's DHCP list. The router currently functions with two other systems accessing the internet through it, and does not have any blocking or firewall enabled.
PING - Used ping to attempt connection to local machine, router, and WAN. Successful connection to local machine (assumed through local loopback) and Failed connections to router and WAN.
From this it seems that the system recognizes the card but fails to operate it, which implies to me a problem with the driver. However, the driver is present on the installation disk and is used without issue to perform a net-install. I am not clear what might happen between the CD boot and the HD boot that might cause this functionality to cease.
Some of the other articles that I have read suggest that it might be fixed by installing a DNS-Server on the localhost and referencing it instead of the router. Similar lines have suggested disabling IPv6. I have tried the latter of these two suggestions with no success (the system now has IPv6 enabled again). I do not think that the DNS would be the solution, because the problem seems to be with communication and not domain name mapping. To avoid using DNS services, I have been using IP addresses only in my attempts to correct the system troubles.
You can pull an IP address from your router and your interface shows as UP but you can not ping the router that is giving you your IP address.
can you browse to the router at 192.168.0.1 or your comcast cable modem at 192.168.100.1
you could bypass the router just for test and hook directly to the comcast modem (need to POwercycle the modem so that it recognizes the new Mac address presented by your NIC and see if it pulls a public address then swap the router back in and go through the power cycle reset process so the comcast will again recognize the Routers Mac address and see if you can again pull a private address from the router.