Call for help with network hardware setup
I am using Debian and trying to set up a couple of ethernet cards. I've seen strange behavior. Have I found a bug? Done something stupid? Rather than clog the WLUG list with details, I have put my question on a web page, which I will update as I learn more: http://www.free-comp-shop.com/ether.html -- Keith
On Fri, Nov 22, 2019 at 01:39:24PM -0500, Keith Wright via WLUG wrote:
I am using Debian and trying to set up a couple of ethernet cards. I've seen strange behavior.
Have I found a bug? Done something stupid?
Rather than clog the WLUG list with details, I have put my question on a web page, which I will update as I learn more:
You have two NICs configured in the same subnet. If you intend to make two subnets for the Green and Red NICs, make sure the subnet addresses doesn't overlap. If you want them to be in the same subnet (why?) then the behavior you see is normal for Weak Host Model systems: https://en.wikipedia.org/wiki/Host_model You can reconfigure your system for Strong Host Model and/or use multiple routing tables and source rules to control which NIC is used for which traffic: https://access.redhat.com/solutions/30564
"Anderson, Charles R via WLUG" <wlug@lists.wlug.org> writes:
Have I found a bug? Done something stupid?
You have two NICs configured in the same subnet. If you intend to make two subnets for the Green and Red NICs, make sure the subnet addresses doesn't overlap.
In production they are _very_ different subnets. The LAN is 192.168.1.* while the internet address is 66.92.74.188/24. I am just trying to test it all with both cables going to things that I control.
If you want them to be in the same subnet (why?)
As I said, just for testing. Would it help to test with address 192.168.2.1/24 (note 2 in second to low order byte). I've never tried to use such an address, and I am not sure how to configure the other machines to use it without trying to route through gateway to the internet.
then the behavior you see is normal for Weak Host Model systems:
Thank you for that link. I added it to the web page and will continue to update as I learn more.
You can reconfigure your system for Strong Host Model and/or use multiple routing tables and source rules to control which NIC is used for which traffic:
Roger. Will read. -- Keith
On Fri, Nov 22, 2019 at 03:04:21PM -0500, Keith Wright wrote:
In production they are _very_ different subnets. The LAN is 192.168.1.* while the internet address is 66.92.74.188/24. I am just trying to test it all with both cables going to things that I control.
If you want them to be in the same subnet (why?)
As I said, just for testing. Would it help to test with address 192.168.2.1/24 (note 2 in second to low order byte). I've never tried to use such an address, and I am not sure how to configure the other machines to use it without trying to route through gateway to the internet.
Yes. If you want to test with a test router and test network, then you need to set up a test network and plug a test system into it. If you have this now: realsystem---[REAL-LAN switch]---[REAL-LAN-interface realrouter REAL-WAN-interface]---Internet REAL-LAN-interface is presumably 192.168.1.1/24. REAL-WAN-interface is whatever your ISP gave you. Then this could be your test network: testsystem---[TEST-LAN switch]---[TEST-LAN-interface testrouter TEST-WAN-interface]---[REAL-LAN-Switch] TEST-LAN switch could just be a (crossover) ethernet cable if you don't want more than one test system or don't have another switch. testrouter is your new Debian system. testsystem == 192.168.2.10/24, default gateway == 192.168.2.1 TEST-LAN-interface == 192.168.2.1/24 TEST-WAN-interface == 192.168.1.xxx/24 (a free IP on your real network), default gateway 192.168.1.1
participants (2)
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Anderson, Charles R -
Keith Wright