[ipxe-devel] MTU ISSUE with the iPXE

[Christian Nilsson]

Maybe this commit explains it somewhat;
https://git.ipxe.org/ipxe.git/commit/16aed6e5ce808615df95c7767b4dd8793c398d93
Simply put iPXE does not support larger then 1500 mtu - it would
probably require driver rewrites, but for some drivers it might just
be to change MTU constants, to know more we need to know which driver
you are using.

One other issue and reason that might mean this will never be
implemented is issues with different hardware, for example SNP and
UNDI which is setup by Firmware/BIOS/ROM is unlikely to support
anything larger then 1500 and for those it mean a inconsistent
behavior. Which care is taken to avoid.

On Tue, Mar 14, 2017 at 5:15 AM, W Drinsun <be.wu at live.com> wrote:
> I set the mtu to 4088 like below conf
>
> set mtu 4088
>
> set keep-san 1
>
> set netX/mtu 4088
>
> set netX/keep-san 1
>
> set netX/gateway 0.0.0.0
>
> set net0/mtu 4088
>
> set net0/keep-san 1
>
> set net0/gateway 0.0.0.0
>
>
>
>
>
> but still work with 1500 mtu
>
>
>
> C:\Users\bewu>ping 192.168.7.157 -f -l 2000
>
>
>
> Pinging 192.168.7.157 with 2000 bytes of data:
>
> Reply from 192.168.7.131: Destination host unreachable.
>
> Reply from 192.168.7.131: Destination host unreachable.
>
> Reply from 192.168.7.131: Destination host unreachable.
>
> Reply from 192.168.7.131: Destination host unreachable.
>
>
>
> Ping statistics for 192.168.7.157:
>
>     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
>
>
>
> C:\Users\bewu>ping 192.168.7.157 -f -l 1000
>
>
>
> Pinging 192.168.7.157 with 1000 bytes of data:
>
> Reply from 192.168.7.157: bytes=1000 time=420ms TTL=64
>
>
>
> Do you know has any patch or solution for working with 4088 mtu
>
> Sent from Mail for Windows 10
>
>
>
>
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