Jumbo Frames

[plink212]

I am trying to enable jumbo frames on my nforce 430 based motherboard, however when I do ifconfig eth0 mtu 9000 or anything greater than 1500 i get SIOCSIFMTU: Invalid argument.

lspci
00:10.0 PCI bridge: nVidia Corporation MCP51 PCI Bridge (rev a2)
ifconfig
eth0 Link encap:Ethernet HWaddr 00:15:58:11:09:A9
inet addr:192.168.1.4 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:693153 errors:0 dropped:0 overruns:0 frame:0
TX packets:500454 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:986671593 (940.9 Mb) TX bytes:54155600 (51.6 Mb)
Interrupt:10
ethtool
Settings for eth0:
Supported ports: [ MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: external
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: yes

uname -a
Linux mythtv 2.6.18-ck1-r2 #2 SMP Sun Nov 19 12:43:53 GMT 2006 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4800+ AuthenticAMD GNU/Linux

[plink212]

so no ideas about jumbo frames in the kernel driver?

Tim