I'm trying to use DPDK on AWS i3.metal instances. I have the code built with AWS vfio-patches. In order to be logged into the machine on one NIC while having a free ENA NIC for DPDK, I attached a second NIC.

./dpdk-devbind.py is able to see the second NIC, and bind to it. All that's working fine. However, by default this 2nd NIC does not have an IP address.

Meanwhile code needs a hostname or IP address of the client and server. How do I get an IP address associated with this 2nd NIC? And do I need to do some sys-admin work to ensure traffic in and out of the DPDK bound vfio-pci NIC is kept separate from the first NIC?

As far as I can see the correct approach is to:

# setup second NIC to have an IP address and make sure UP before dpdk-devbind:
* sudo ip addr add <some-valid-ipv4-addr> dev ens1 label ens1:1
* sudo ip lin set ens1 u[

before I do DPDK bind.

The NIC, when AWS adds it, starts off down without an IP address by default:

ubuntu$ lspci | grep Ether

04:00.0 Ethernet controller: Amazon.com, Inc. Elastic Network Adapter (ENA)
05:00.0 Ethernet controller: Amazon.com, Inc. Elastic Network Adapter (ENA)
ubuntu$ sudo ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens785: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP group default qlen 1000
    link/ether 0a:0f:1f:db:ca:73 brd ff:ff:ff:ff:ff:ff
    inet 172.31.17.144/20 brd 172.31.31.255 scope global dynamic ens785
       valid_lft 3544sec preferred_lft 3544sec
    inet6 fe80::80f:1fff:fedb:ca73/64 scope link
       valid_lft forever preferred_lft forever
3: ens1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0a:06:15:14:95:05 brd ff:ff:ff:ff:ff:ff

Once I bind 'ens1' dpdk-devbind reports it as bound -AND- it no longer appears in `ip a`:

Network devices using DPDK-compatible driver
============================================
0000:05:00.0 'Elastic Network Adapter (ENA) ec20' drv=vfio-pci unused=ena

Network devices using kernel driver
===================================
0000:04:00.0 'Elastic Network Adapter (ENA) ec20' if=ens785 drv=ena unused=vfio-pci *Active*

$ ip a
ubuntu@ip-172-31-17-144:~/Scripts$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens785: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc mq state UP group default qlen 1000
    link/ether 0a:0f:1f:db:ca:73 brd ff:ff:ff:ff:ff:ff
    inet 172.31.17.144/20 brd 172.31.31.255 scope global dynamic ens785
       valid_lft 3314sec preferred_lft 3314sec
    inet6 fe80::80f:1fff:fedb:ca73/64 scope link
       valid_lft forever preferred_lft forever