[Solved] Modem connection resets with El Capitan

[Fairlyodd45]

Hi all,

First post with a real issue. I reinstalled El Capitan on my Dell Inspiron 518 and I can no longer browse the internet without resetting my cable modem ? This is quite strange considering the system ran smoothly for well over a year. The logs on the modem state that I am having issues with IPv6 foreword denials which are being blocked by the IPv6 firewall that is currently disabled on the modem. Now the real strange thing is that I can browse without issue on my Win10 system on the same network. Not really sure what the issue is, but I have already replaced the modem three times this week and even had the tech come out to check the lines and all connections through Comcast, so that is obviously not the issue. Could this be an issue with the Realtek RTL811 Kext that I am using ? I have tried everything I can think of to get this to work, but now I am asking for help because this is quite frustrating to say the least. These are the specs for the 518 https://www.cnet.com/products/dell-inspiron-518/specs/ The only thing that differs from the original specs is that I am currently running my installation on external USB Solid state Hard Drives since El Capitan does not support my SATA Controller.

 

[BreBo]

@Fairlyodd45, please update your profile (personal details) with your build (Motherboard or Model, CPU and Graphics Card).

Profiles need to contain at least your primary system to assist others with helping you.

Try to configure IPv6 as Link-local only.

System Preferences > Network > Ethernet > Advanced

 

[Fairlyodd45]

@Fairlyodd45, please update your profile (personal details) with your build (Motherboard or Model, CPU and Graphics Card).


Try to configure IPv6 as Link-local only.

System Preferences > Network > Ethernet > Advanced

View attachment 241833

I tried configuring IPv6 as Link-local and even disabled the IPv6 Firewall in the modem with no luck, so what I did was I checked ID of the exact Realtek chipset that was used on this board and found out it was a "C" series, so I added the "C" to the info.plist file in the RTL811 kext
<key>IOPCIMatch</key>
<string>0x816810ec 0x81681186C</string>
and rebooted and it is working just fine. No idea why this would make a difference, but apparently it does ?

Thanks again for your help mate. \m/