[GTALUG] Ethernet alias triggering network security warnings

Kevin Cozens kevin at ve3syb.ca
Wed Apr 27 22:26:46 EDT 2022


Greetings, all.

I am using an embedded system that is running a version of an Ubuntu distro. 
The embedded system is being set up so that the physical Ethernet port will 
have two aliases. One is eth0:0 and the other is eth0:1.

eth0:0 is set to get an IP address via DHCP when a network cable is plugged 
in (assuming a DHCP server is available). The eth0:1 is set to have a static 
IP address. This allows an installer to connect a laptop to the system and 
do some onsite configuration (setting WiFi parameters).

The network settings I'm using are:
   auto eth0:0
   iface eth0:0 inet static
   address 192.168.100.110
   netmask 255.255.255.0
   gateway 192.168.100.1

   auto eth0:1
   allow-hotplug eth0:1
   iface eth0:1 inet dhcp

This was working at one point but lately a Windows machine on the network 
will start complaining either about possible ARP poisoning or it will say 
there is a duplicate IP address. The program on the Windows box reporting 
the problem is esset Internet Security. I know nothing about the program. It 
is on the machine of the person preparing boxes to be sent out in to the field.

When I check the system that seems to have triggered the duplicate IP 
address warning I see no duplication. I have checked all the MAC addresses, 
inet v4 and inet v6 IP addresses listed by the ifconfig program.

Does anyone on this list know anything about that security program or why 
the person setting up the embedded systems would be seeing the duplicate IP 
warnings?

-- 
Cheers!

Kevin.

http://www.ve3syb.ca/               | "Nerds make the shiny things that
https://www.patreon.com/KevinCozens | distract the mouth-breathers, and
                                     | that's why we're powerful"
Owner of Elecraft K2 #2172          |
#include <disclaimer/favourite>     |             --Chris Hardwick


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