if_bridge and ng_netflow

Fbsd8 fbsd8 at a1poweruser.com
Sat Aug 10 13:51:28 UTC 2013

Volodymyr Kostyrko wrote:
> Hi all.
> I have one machine with bridge configured. Recently I thinked about 
> capturing all traffic on the bridge with ng_netflow.
> 1. ng_ether doesn't attach to bridge0 interface:
> # ngctl list | grep ether
>   Name: rl0             Type: ether           ID: 00000034   Num hooks: 2
>   Name: ste0            Type: ether           ID: 00000035   Num hooks: 2
>   Name: wlan0           Type: ether           ID: 00000036   Num hooks: 2
> 2. If I attach all physical interfaces to netflow I get no statistics 
> for data originating from server. I.e. I see all inbound traffic but I 
> see no outbound traffic.
> Maybe I'm just doing everything wrong? I'm adding interfaces to netflow 
> this way:
>     connect wlan0: netflow0: upper iface2
>     connect wlan0: netflow0: lower iface3
>     connect netflow0: netflow0: out2 out3
> 3. Ok, I can do this other way (sorry, I'm bad at netflow scripting):
> mkpeer eiface ether ether
> rmhook ngeth0: ether
> ifconfig ngeth0 up
> ifconfig bridge0 span ngeth0
> And again I see only inbound packets. I see no packets coming from me.
> Is there any other working way to get stats from bridge interface?

if_bridge is relatively new in FreeBSD. Netgraph precedes if_bridge and 
is un-aware of if_bridge. Change your if_bridge definition to a
ng bridge definition and everything your trying to do should fall into 

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