em device hangs on ifconfig alias ...

[Atanas]

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.

That's the primary reason I stay away from the on-board 1Gbps em NICs 
that almost every Intel server board nowadays comes with. I simply 
disable them and use a good old (and cheap) Intel PRO/100 fxp compatible 
PCI NIC instead. It's fast enough and doesn't reset the card when you 
add an alias. The only downside is that it gives you 100Mbps at most.

Does anybody know a better NIC driver alternative when dealing with lots 
of IP aliases?

I have some newer machines with 2 Broadcom chips on-board. I plan to 
give them a try at some point in the future, but I'm not sure how stable 
the bge driver is when compared to fxp and em.

Regards,
Atanas