Output errors on bonded interface

Today I’ve been busy to add new hardware. A Netoptics Slim-TAP to monitor the external network of our Head Office.

Ones I’d connected everything, I started to configure the monitoring interface using the following instructions.

nsm# kldload ng_ether
nsm# ifconfig sf0 -arp promisc up
nsm# ifconfig sf1 -arp promisc up
nsm# ngctl mkpeer . eiface hook ether
nsm# ngctl mkpeer ngeth0: one2many lower one
nsm# ngctl connect sf0: ngeth0:lower lower many0
nsm# ngctl connect sf1: ngeth0:lower lower many1
nsm# ifconfig ngeth0 monitor up

When I checked the interface status, I noticed that their where output errors on the outgoing interface, which shouldn’t be happing!

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
ngeth  1500 <Link#14>     00:00:00:00:00:00        0     0        0  7443     0

After searching the Internet on the same issue, I came across a problem report from FreeBSD.

When using netgraph to “bond” two syskonnect gige interfaces together for a packet capture application, we see output errors on the pseudo interface that is the sum of the number of packets input on the two syskonnect NICs. Examination of the code reveals that this is because the packets cannot be transmitted out the pseudo interface.

Hmm, this sounds familiar! When I’d patched, rebuild the kernel and rebooted the problem was solved.

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
ngeth  1500 <Link#14>     00:00:00:00:00:00      153     0        0     0     0

If you have similar problems, check out the problem report.