vlans changed?

Jon Simola jsimola at gmail.com
Wed Jan 19 13:22:52 PST 2005


On Wed, 19 Jan 2005 13:01:52 -0800, Charlie Schluting
<charlie at schluting.com> wrote:

> Now, in 5.3, the only thing I can get working is to configure the em0 int with
> the IP, and set the trunk to have the native vlan corresponding to that IP. Weird.

Sounds like you're not getting the module loaded. By your description
above, you're no longer sending tagged frames over the trunk.

My rc.conf bits:

ifconfig_em1="up media auto"
cloned_interfaces="vlan100"
ifconfig_vlan100="inet xx.xx.xx.254 netmask 0xffffff00 vlan 100 vlandev em1"

> Also, is there a way to stop em(4) from stripping dot1q tags in hardware? I'd
> like to see them with tcpdump. What kind of a performance hit does this involve?

# tcpdump -c4 -nvvvei em1
14:24:52.445480 00:30:48:72:f3:0b > 00:09:5b:fc:e4:5f, ethertype
802.1Q (0x8100), length 1532: vlan 100, p 0, ethertype IPv4, IP0
bad-hlen 0
14:24:52.445500 00:30:48:72:f3:0b > 00:09:5b:fc:e4:5f, ethertype
802.1Q (0x8100), length 279: vlan 100, p 0, ethertype IPv4, IP0
bad-hlen 0
14:24:52.445518 00:30:48:72:f3:0b > 00:c0:05:04:00:f0, ethertype
802.1Q (0x8100), length 144: vlan 100, p 0, ethertype IPv4, IP0
bad-hlen 0
14:24:52.445539 00:30:48:72:f3:0b > 00:0f:3d:64:f4:23, ethertype
802.1Q (0x8100), length 72: vlan 100, p 0, ethertype IPv4, IP0
bad-hlen 0

Seems to work fine (it's the -e switch that does it).

Hope that helps.


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