Nic_router and multiple NIC drivers in the same domain

General
1

Hi

In our testing environment we encountered a problem when two NIC drivers connected to the same domain (see config example below).

<config>
  <domain name="uplink">
    <nat domain="downlink" udp-ports="2000" tcp-ports="2000" icmp-ids="2000"/>
  </domain>

  <domain name="downlink" interface="10.10.10.250/16">
    ...
  </domain>

  <policy label="eth1 ->" domain=uplink"/>
  <policy label="eth2 ->" domain=uplink"/>
  <default-policy domain=downlink"/>
</config>

Both Ethernet ports, of the device under test, are connected to the same test network.

What we observed:

  • all ports on the switches were blinking in sync
  • in wireshark we could see, that ARP requests for the gateway were sent out on both interfaces in really fast succession
  • after the run script was terminated the network recovered most of the time, sometime some switches needed to be restarted

This leads to some questions:

  1. are the described observations what one should expect to happen?
  2. would it have made a difference if the two Ethernet ports were in two separated networks?
  3. Is there a way to prevent a domain from accepting multiple connections?
    • I did not see anything in the README. In general accepting multiple connections is what one wants