Endian Jumbo Frame

[Guest]

[bautzen]

Hi to all, I would like to know if it could be possible to change MTU to 2 internal NIC on efw2.4. I other words I have something like this:

SCENARIO:
[SERVER SBS 2003 WITH ISA 2004]
    * NIC1 to internal lan (10.1.0.6/16) with MTU 1500 (it's main gateway for the clients)
    * NIC2 to DMZ lan (172.16.0.100) with MTU 1500. Through this inet my LAN clients exit to intenet

[ENDIAN EFW 2.4]
    * NIC1 to internal lan and for OpenVPN connections (10.1.0.254/16) and (10.3.0.254/16) MTU1500
    * NIC2 to DMZ (172.16.0.254/24) MTU1500
    * NIC3 to "Service LAN" for NAS, iSCSI, NFS etc (10.2.0.254/16) MTU1500
    * NIC4 to ISP Router (192.168.0.253/24) and gw 192.168.0.254 (router cisco) MTU1500

My SBS2003 Premium doesn't accept a third NIC for Service LAN for that reason I have to route the traffic through endian gateway (10.1.0.254) to reach 10.2.0.0 net
Now form my SBS I can quite open my NAS on 10.2.0.10 and connect to iSCSI Target correctly but the performance are non so good.
My NAS has MTU 9000 and if I create a new server on Service LAN and I enable jumbo frame I can quite ping the NAS correctly (ping -f -l 8900 10.2.0.10). 
If I enable Jumbo Frame on my NIC1 on SB2003, after I have the bottleneck on my endian firewall!!!
MY questions are:
1) If I enable the jumbo frame on internal NIC1 of my SBS2003, could I have some problems on client's side? The NIC1 is also default gateway for the lan to surf internet!!!!
2) There is a way to change MTU on endian for the NIC1 and NIC3 and if yes what problems   could I have for the web surfing and publishing of my intranet web applications?

If someone have a better solution, please let me know

Sincerely best regards

Patrick