Routing multiple network interfaces

Networking & Firewalls
8

Hi Fred,

Your post was most helpful. I have made my config work now, which is very pleasing. There were two things I had not got correct or appreciated:

  1. My Debian /etc/network/interfaces config file was not correct. I had it as follows (not working)
source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface (management)
auto eth0
iface eth0 inet dhcp # 10.0.0.10 dhcp address reserved

# The LAG network interface (storage)
auto eth1
iface eth1 inet static
    address 10.0.1.10      # not enough to 
    netmask 255.255.255.0  # ... get an IP assigned to eth1

My issue was eth1 was not getting the IP requested, so I had to add two more directives:

# The LAG network interface (storage)
auto eth1
iface eth1 inet static
    address 10.0.1.10
    netmask 255.255.255.0
    network 10.0.1.0         # added or no eth1 interface address set
    broadcast 10.0.1.255     # added also
  1. LACP will not give me more bandwidth on a single session. I have confirmed this using iperf3 at both ends. The maximum one iperf3 session can get is ~1Gbps. Two iperf3 sessions (two servers, two clients) get 1Gbps, however. Nice.

The realisation of #2 is disappointing as backup storage write performance is no better, although I could overlap backups and I have gained resilience, which is welcome.

Thanks for the pointers. Your attention is really appreciated. I love these forums!

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