FreeBSD 10.0-R connected to Cisco switch (in 'trunk' mode with native VLAN) - doesn't work?

[Hrant Dadivanyan]

> 
> Hi,
> 
> I've got a Cisco 3750X switch a colleague is setting up. We've got this 
> configured - but it doesn't seem to talk nicely to our FBSD 10.0-R box, 
> looks like some kind of VLAN issue (but shouldn't be).
> 
> 
> Switch side - the port is configured with:
> 
>  switchport trunk encapsulation dot1q
>  switchport trunk native vlan 2000
>  switchport trunk allowed vlan 2000,2200-2300
>  switchport mode trunk
> 

Hi Karl,

I'm not sure whether it's on by default, but many Cisco switches (including
all in 3750 family) can tag native vlan, so no a packet will leave ports
untagged.
    no vlan dot1q tag native
in configuration mode will switch this off.

Thank you,
Hrant

> 
> >From what I understand this tells the Cisco to present all the 'allowed' 
> VLAN's to the port, and that untagged traffic traversing the port should be 
> sent/received as VLAN 2000?
> 
> So, we connect our BSD box and do:
> 
>    ifconfig bge0 inet 192.168.100.10 netmask 255.255.255.0
> 
> But we can't ping another host connected on the network, on '192.168.100.1'.
> 
> The above ifconfig uses no VLAN spec, but that should be covered by the 
> 'trunk native vlan'?
> 
> 
> The only way we can fix this - is to take the system 'as-is' and change the 
> Cisco port to:
> 
>    switchport mode access
>    switchport access vlan 2000
> 
> This sets the port to be 1 VLAN only, and sets that VLAN to VLAN 2000 - so 
> traffic traversing the port will be untagged, but carried as part of VLAN 
> 2000.
> 
> I've been told in theory the bottom config should be the 'same' as the 
> previous one (i.e. untagged traffic is treated as VLAN 2000).
> 
> But with the top config - the BSD box can't connect anywhere, with the 
> bottom config (with the BSD box setup the same) - it can.
> 
> 
> Presuming someone here has used Cisco kit with FreeBSD - can anyone see why 
> the top config doesn't work? - The guy setting up the switches says he 
> always uses the top config - and hasn't had an issue with it, but this 
> obviously doesn't work with our FreeBSD boxes.
> 
> I would say we'd try it with a different O/S but at the moment, all the kit 
> on 'our' side is FreeBSD based...
> 
> 
> Cheers,
> 
> -Karl
> 
> 
> 
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"

-- 
Hrant Dadivanyan (aka Ran d'Adi)		hrant(at)dadivanyan.net
/* "Feci quod potui, faciant meliora potentes." */       ran(at)psg.com