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Author Topic: Jumbo Frames on Dir-855 ???  (Read 6028 times)


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Jumbo Frames on Dir-855 ???
« on: October 23, 2008, 09:53:33 AM »

I just ordered a NAS box and they highly recommend using jumbo frames for performance. 
i.e. Lower CPU utilization and higher throughput.

The question is, How do I accomplish this on the DIR-855?

My NIC's support up to 9000 Byte jumbo frames but of course it is pointless if the router does not.

It appears my maximum MTU size is 1500 with current firmware. 1.12

Thanks for any input.


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Re: Jumbo Frames on Dir-855 ???
« Reply #1 on: October 23, 2008, 10:21:59 AM »

Please understand that Jumbo Frames are for LAN traffic only. That being said any frame headed for the NAT will have to ibe inspected for WAN traffic and if the CPU in the switch is handling LARGE frames this can cause slowdowns.

The SWITCH CPU can handle 4k+ frames but the NAT cpu can not.


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Re: Jumbo Frames on Dir-855 ???
« Reply #2 on: October 23, 2008, 11:04:33 AM »

Thanks for the quick reply.
I'm only looking for Jumbo Frames over the LAN with wired connections to the DIR-855.
So, when you say NAT I'm a bit confused.
I thought NAT was Network Address Translation and didn't apply to my wired LAN connections.
Is this not the case? ???

If it is, would using static IP addresses allow me to use jumbo frames?
I'm also running multiple NICs in these machines to multiple subnets.
One subnet is the DIR-855 and the other is the DGL-4100.
I am able to configure the DGL-4100 to jumbo frames so maybe I'll just use that subnet for NAS access.
Then use the DIR-855 subnet for http, ftp, etc.

One final thought, I'm also running Vista on these wired computers so wouldn't the use of IPv6 eliminate the need for NAT ?