jumbo packets on em card.

Sharad Chandra sharadc at in.niksun.com
Tue Apr 29 12:22:39 UTC 2008


 ,---- [Jeremy Chadwick wrote:]
| On Tue, Apr 29, 2008 at 04:13:13PM +0530, Sharad Chandra wrote:
| > I am getting a problem in setting em card to 1000baseTX. It shows "active
| > status" with 100baseTX but as soon as i run "ifconfig em1 media
| > 1000baseTX mediaopt full-duplex", it says *no carrier*. how can i set it
| > to 1000base?
|
| The PHYs support auto-negotiation of speed and duplex, as per the 802.3
| standard.
|
| Do you have a gigabit switch?  If so, does auto-negotiation (e.g. no
| "mediaopt" or "media" settings) work?  If not, is the switch a managed
| switch?  If so, try explicitly setting the port on the switch to
| 1000mbit, full duplex.  If not, then consider buying another switch.
| Many consumer/residential switches do not do auto-negotiation properly,
| resulting in "no carrier" or worse (bad throughput).

No, I am not using any switch. It is back-to-back connection. It is only 
requirement for me.

|
| > And is it possible any how to send *jumbo packets* on this card or on bge
| > card (bge card is working with 1000base)? I tried nemesis tool, but i
| > don't think it can send bigger packets. BPF also seems to have limitaion
| > upto 2K.
|
| man 4 em
| man 4 bge
|
| Keep in mind that if you use jumbo frames, your **entire network** needs
| to use jumbo frames.  You cannot mix-and-match frame sizes.  Chances are
| your ISPs or your co-lo provider doesn't support jumbo.

-- 
`----

--
Thanks
Sharad Chandra


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