# Doubt regarding the e1000 JF Support



## linuxunix (Nov 24, 2010)

I read these lines soemwhere:

```
Adapters based on the Intel(R) 82542 and 82573V/E controller do not
 support Jumbo Frames. These correspond to the following product names:
 Intel(R) PRO/1000 Gigabit Server Adapter
 Intel(R) PRO/1000 PM Network Connection
```

I have FreeBSD 8.1 64 bit VM running on the ESX 4. I have selected e1000 as network Adapter.
When I run the command:

```
ifconfig em0 mtu 9000
```

The Command Works.
If e1000 doesnt support Jumbo Frames how did it took that value.
Pls Clarify.


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## wblock@ (Nov 24, 2010)

em(4) supports several variations of the hardware.  Some do jumbo frames, some don't.  It could easily get a lot weirder in a VM, depending on how the VM emulates the card and the mode of networking used.

`% pciconf -lv | grep -A3 em0`
should show which of the Intel cards is being emulated.  Check the man page link above to see what it says about that hardware.


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