netdev - Re: Realtek r8168C / r8169 driver VLAN TAG stripping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 27 Jan 2011 21:01:44 +0530
From:	Anand Raj Manickam <anandrm@...il.com>
To:	Francois Romieu <romieu@...zoreil.com>
Cc:	netdev@...r.kernel.org, Hayes <hayeswang@...ltek.com>
Subject: Re: Realtek r8168C / r8169 driver VLAN TAG stripping

On Thu, Jan 27, 2011 at 8:37 PM, Francois Romieu <romieu@...zoreil.com> wrote:
> Anand Raj Manickam <anandrm@...il.com> :
> [...]
>> We upgraded to 2.6.36 kernel . The result is SAME.
>> The VLAN tag gets stripped ;-)
>> Do let me know if you need more info .
>

> - ip addr show

3: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:17:54:00:f6:62 brd ff:ff:ff:ff:ff:ff
    inet 172.16.1.1/16 brd 172.16.255.255 scope global eth0
    inet6 fe80::217:54ff:fe00:f662/64 scope link
       valid_lft forever preferred_lft forever

8: eth0.50@...0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc noqueue
    link/ether 00:17:54:00:f6:62 brd ff:ff:ff:ff:ff:ff
    inet 172.16.10.10/24 brd 172.16.10.255 scope global eth0.50
    inet6 fe80::217:54ff:fe00:f662/64 scope link
       valid_lft forever preferred_lft forever


> - ethtool -k eth0

Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: off
scatter-gather: off
tcp segmentation offload: off
udp fragmentation offload: off
generic segmentation offload: off



> I do not get the "VLAN tag gets stripped" concept, especially on Tx.
> Does it mean "no packet" or "a packet whose content is wrong" ?

Sorry for not being clear ;-)

When we transmit a packet with VLAN TAG , the TAG get stripped when
transmitted through the device , the other end trunk port / sniffer
does NOT see a TAG.
Similarly , when a VLAN Tagged packet is sent from the other end , The
TAG gets stripped by the device , We DONOT see the tag .

I use tcpdump -i eth0 -n -nn -e vlan 50
to see if the packets are gettin tagged or NOT .

The same config works on forcedeth


Thanks,
Anand

>
> --
> Ueimor
>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html