# Question about building a LAGG and odd behavior



## rtbates63 (Oct 25, 2013)

Question about building a lagg(4) and odd behavior.

I have set up a system using FreeBSD 9.2. We are using a HP switch, ports B9, B10, B11 are LACP LAGG, port B12 is a standard port. On the server:

NIC em0 is connected to port B12, IP address 172.18.1.134
NICs em1,em4,em5 are connected to HP ports B9, B10, B11, IP address 172.18.1.138

In /etc/rc.conf we have:

```
ifconfig_em0="inet 172.18.1.134 netmask 255.255.255.0"
ifconfig_em1="up polling"
ifconfig_em4="up polling"
ifconfig_em5="up polling"
cloned_interfaces="lagg0"
ifconfig_lagg0="up laggproto lacp laggport em1 laggport em4 laggport em5 172.18.1.138/24"
defaultrouter="172.18.1.2"
```

When it seems to work. But when I disconnect the single CAT5 172.18.1.134 the lagg0 goes down and I can not ping the server on 172.18.1.138. Also, I noticed on the HP switch most of the traffic is going over server port em0 only a small portion of traffic is going over the lagg interface. (See HP Port Usage image attached).

Can you help me with this configuration?

Thank you.


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## SirDice (Oct 25, 2013)

You have two interfaces, em0 and lagg0, in the same subnet. That's never a good idea.


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## rtbates63 (Oct 25, 2013)

Yes, I know.  But when I remove the IP off of em0, I lose the connection to the LAGG.  That's the odd behavior. Couldn't get LAGG to come up without adding the one extra direct connect port.

Also, I originally had the em0 defined so I could finish config from my desk (not the server room). Once I configured LAGG I attempted to remove the em0 port and reboot. LAGG never came up. Had to physically go to the server room and config_ure_ the em0.


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## torqueturns (Nov 12, 2013)

Try getting rid of the POLLING option, I've never used those Intel NICs with POLLING and LAGG together.


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