From: Ulrich
To: Kevan
Date: 17-MAR-16

But after I had restored the network setup, I found some instructions on the internet and those are surprisingly simple (and they worked out of the box). All you have to do is to plug your A2971E into the same switch as your desktop and issue just one command:

/sbin/ifconfig eth0:0 10.0.0.2 netmask 255.255.255.0

What it does: it creates a "virtual" network card on top on the real one (here called eth0) where your computer has the network address 10.0.0.2. You could also create more of those like eth0:1, eth0:2 etc. You can disable this virtual card with "/sbin/ifconfig eth0:0 down" if it is no longer needed.

The advantage: this setting is not permanent and is gone after the next reboot (which is exactly what you would like, because you use it only once). The other advantage: you do not have to reconfigure your network after you changed the address to your institute network, since the other network is running over the same switch anyway. So after the reboot of the A2971E the "Connect" command works immediately to the new address.


From: Kevan
To: Kevan
Date: 29-MAY-19

Here is an example dhcpcd.conf file, from /etc/dhcpcd.conf on a Rasbian system running on a Raspberry Pi 3B+. The same file should work on any Linux machine using dhcpcd.conf(5). We assume the network manager has assigned the name "eth0" to the wired Ethernet interface. In newer Linux machines, the wired Ethernet interface is likely to be given what's called a "predictable network interface name", which can end up being a long alpha-numeric string containing, among other things, the interface's MAC address. Use "ifconfig" at the command line to get the wired Ethernet interface name and substitute that name in the file below. This example DHCP configuration file sets up the wired Ethernet to get its address from a DHCP server, but if we get no DHCP response, we revert to a local network with a static IP address. Thus we can connect our Linux machine directly to the LWDAQ Driver, bring down the wired ethernet with "ifconfig eth0 down", bring it up again with "ifconfig eth0 up" and we will be able to communicate.

# Dynamic Host Configuration Protocol Configuration File.
# See dhcpcd.conf(5) for details of the options. This 
# configuration directs the DHCP process to try and get
# a dynamic IP address, along with domain name servers and
# routers. But if we get no answer from a DHCP server, we
# revert to a local, static IP address.

# Allow users of this group to interact with dhcpcd via the control socket.
controlgroup wheel

# A static IP configuration, defined under a profile name, for use later
# as a fallbcack for eth0.
profile local_network
static ip_address=10.0.0.236/24
static routers=10.0.0.1

# Select the eth0 interface.
interface eth0

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
clientid

# Persist interface configuration when dhcpcd exits.
persistent

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search
option host_name, classless_static_routes

# Most distributions have network time protocol (NTP) support, 
# so use it if available.
option ntp_servers

# Respect the network MTU. This is applied to DHCP routes.
option interface_mtu

# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac private

# If the DHCP server does not respond, fall back to the static local
# network profile.
fallback local_network