On Wed, 2009-12-30 at 14:18 +0000, Rob Malpass wrote:
> Hi all
>
> Season's greetings.
>
> Can anyone help fill (one of many) gaps in my networking knowhow?
>
> I got a Netgear ReadyNAS Duo for Christmas and performance has been
> really slow. It seems the MTU is the culprit. Two problems:
> 1) Should the MTU on the NAS (I've only ever seen MTU on routers
> before) be set to the same as the MTU on the router?
> 2) It seems the ReadyNAS insists on setting its own MTU as I've told
> it to "Auto-negotiate" the Speed / Duplex mode. The other two
> options for this setting are full or half duplex at 100MBps. I tried
> both of these yesterday which resulted in the ReadyNAS basically dying
> and only a factory reset brought it back so I'm loathe to do it again.
>
> And this brings me to a 3rd question come to think of it....
>
> 3) Is it the MTU that will be affecting performance or is this a red
> herring?
>
> Cheers
> Rob
> --
> Please post to: Hampshire@???
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> --------------------------------------------------------------
This may be nothing, but you are not blocking ICMP at all? I made a note
of this from an old support job for similar issues:
* Router / Network Device between the sending server and the device
having a smaller MTU and ICMP messages blocked. Although the connection
is negotiated server to server, anything in the path that blocks ICMP
Message TYPE 3 (Destination unreachable) Code 4 (Fragmentation Needed
and Don't Fragment was Set) can cause this problem.
This is probably *not* the issue but I HIH....
