HOWTO: Create a BOND with RHEL7

Let’s say you have a few spare NICs and want to put them together in a (active/passive) bond.  What do you do?

Well, this is pretty straight-forward.

First, connect via SSH to an IP on a NIC that WILL NOT be part of the bond.

Using ‘nmcli’ – remove references to the NICs you want IN the bond and reload nmcli:

[root@rhce ~]# nmcli con del p4p1 p4p2
Connection 'p4p1' (92d6456d-16bd-4eae-9ecb-386cb4ce4d29) successfully deleted.
Connection 'p4p2' (e52eca2f-8c84-428d-8959-93e85f4b03f3) successfully deleted.
[root@rhce ~]# nmcli con reload

Next, with nmcli, create the bond:

[root@rhce ~]# nmcli con add type bond ifname bond0 con-name bond0 mode active-backup miimon 100 ip4
Connection 'bond0' (5886c4c3-6ed7-4785-be41-7ef4c6f29373) successfully added.

Now, the bond is just an IP at this point in time; there are no NICs associated with it.  Time to add the two NICs (p4p1 & p4p2) in:

[root@rhce ~]# nmcli connection add type bond-slave ifname p4p1 con-name p4p1 master bond0
Connection 'p4p1' (ef7fd007-af66-43f2-a769-a8916dbf09c9) successfully added.
[root@rhce ~]# nmcli connection add type bond-slave ifname p4p2 con-name p4p2 master bond0
Connection 'p4p2' (d40213dd-4fd7-4a62-ac4c-1cc2d7480284) successfully added.

Optional (I think, but I still do it), modify the bond to have DNS:

[root@rhce ~]# nmcli connection modify bond0 ipv4.dns ","

Now, ‘up’ the bond:

[root@rhce ~]# nmcli con bond0 up

It’ll take about 30 seconds to configure behind the scenes, so set up a continuous ping and wait for it to reply.

The last part of this is testing the functionality.  Start a PING test, pull a cable & see what happens:

$ ping
PING ( 56 data bytes
64 bytes from icmp_seq=52 ttl=64 time=0.357 ms
64 bytes from icmp_seq=53 ttl=64 time=0.301 ms
64 bytes from icmp_seq=54 ttl=64 time=0.359 ms
64 bytes from icmp_seq=55 ttl=64 time=0.339 ms
Pull active cable
Request timeout for icmp_seq 6
<10-45 more times>
Request timeout for icmp_seq 51
64 bytes from icmp_seq=82 ttl=64 time=0.607 ms
64 bytes from icmp_seq=83 ttl=64 time=0.339 ms
64 bytes from icmp_seq=84 ttl=64 time=0.361 ms
64 bytes from icmp_seq=85 ttl=64 time=0.276 ms
64 bytes from icmp_seq=86 ttl=64 time=0.306 ms

Looks like you got an active/backup bond working successfully!