# jumbo frames on via velocity chipset

## KShots

Anyone been able to get this chipset to work? It accepts the following:

```
ifconfig eth0 mtu 7200
```

This claims to work, and an ifconfig confirms that the setting took hold... but...

On the first jumbo frame received, the ethernet interface becomes totally unresponsive, requiring a reboot to recover. I've enabled jumbo frame support in my switch (It's a dell powerconnect 5212). I've taken some precautions on my network, like putting all the jumbo frame machines behind a second router on a separate subnet, so my "normal" network resides on 10.4.12.0/24, and my "jumbo" network resides on 10.4.14.0/24. Everything on 10.4.14.0/24 has an mtu of exactly 7200, while everything on the 10.4.12.0/24 network takes the default mtu of 1500.

----------

## gerdesj

Anything in dmesg?

What kernel version are you using and in particular, what module are you using for this thing ?

Output from:

#dmesg  (just after your NIC freezes - if there is anything)

#lspci -k    (just the bit for your NIC)

#uname -a

Cheers

Jon

----------

## KShots

Wow... I never realized someone replied to this thread  :Sad: 

I'm still facing this issue.

```
gorgon ~ # uname -a

Linux gorgon 2.6.38-hardened-r6 #2 Mon Jul 11 10:19:21 EDT 2011 x86_64 VIA Nano processor L2200@1600MHz CentaurHauls GNU/Linux

gorgon ~ # lspci -k

03:00.0 Ethernet controller: VIA Technologies, Inc. VT6120/VT6121/VT6122 Gigabit Ethernet Adapter (rev 82)

        Subsystem: VIA Technologies, Inc. Device 0110

        Kernel driver in use: via-velocity

gorgon ~ # dmesg | tail

[   56.169254] vt1211: Found VT1211 chip at 0x6000, revision 2

[   56.170305] hwmon_vid: Unknown VRM version of your x86 CPU

[   56.307788] dmeventd (2030): /proc/2030/oom_adj is deprecated, please use /proc/2030/oom_score_adj instead.

[  169.129756] svc: failed to register lockdv1 RPC service (errno 97).

[  169.129810] NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory

[  169.130066] NFSD: starting 90-second grace period

[  370.812003] Velocity is AUTO mode

[  373.684551] eth0: Link auto-negotiation speed 1000M bps full duplex

[  419.132003] Velocity is AUTO mode

[  421.950412] eth0: Link auto-negotiation speed 1000M bps full duplex
```

The dmesg output doesn't seem to mention anything about the issue I'm seeing.

----------

