em device hangs on ifconfig alias ...

[Michael Vince]

Atanas wrote:

> Dan Nelson said the following on 6/28/06 3:52 PM:
>
>> In the last episode (Jun 28), User Freebsd said:
>>
>>> has anyone figured out why the em device 'hangs' for about 30-45
>>> seconds whenever you ifconfig alias a new IP on to the device?
>>
>>
>> The em driver resets the card when you add an IP to it, and unless
>> you've configured your switch not to autodetect fancy features on that
>> port, it may very well take 45 seconds for it to come up.
>>
> For me the em reset actually takes about a second or so per single IP 
> alias. But more aliases you got, longer the timeout becomes. In case 
> you have hundreds (like I do), a single reboot might cost you 
> something like 10-15 minutes of downtime, just for the aliases to come 
> up.
> Does anybody know a better NIC driver alternative when dealing with 
> lots of IP aliases?
>
>
> Regards,
> Atanas
>
> _______________________________________________

For me its IP alias additions take 1 or maybe 2secs, but it is 
noticeable, but really isn't an issue for me.

As far as I have noticed the em driver in 6.1 after being rebuilt is at 
its peak of driver quality, so much in fact that since 6.1 its 
recommended not to even bother with polling with em if you need maximum 
network performance as it won't go any faster, the em driver for 6.1 got 
very large performance improvement compared to older em driver versions 
before 6.1-release, which I suspect got over hacked over time.
I am pretty sure I used to only be able to get 200,300mbits/sec max but 
now I can get up to 850mbits on some and on the lowest side 500mbits/sec 
on others which I suspect is due to cable quality etc.
I am just thankful for it working as it is.

Mike