em device hangs on ifconfig alias ...

[Pyun YongHyeon]

On Thu, Jul 06, 2006 at 07:11:57PM -0700, Atanas wrote:
 > Pyun YongHyeon said the following on 7/6/06 6:03 PM:
 > >
 > >Hmm, that's strange. I've double checked that stock em(4) didn't
 > >generate ARP packets when its addresses were changed. So I made
 > >em(4) generate ARP. Could you see a gratuitous ARP with tcpdump
 > >when you change its address?
 > >
 > I just left a "tcpdump -n arp host 10.10.64.40" on a third machine 
 > sniffing around and tested all em module versions I had (the stock 6.1, 
 > 6-STABLE and 6-STABLE with your patch), but got silence on all three:
 > 

That's odd. I've tested it on CURRENT and I could see the ARP
packet. Are you sure you patched correctly?
If so I have to build a RELENG_6 machine and give it try.

 > EM# ifconfig em1 inet alias 10.10.64.40
 > <nothing>
 > EM# ifconfig em1 inet -alias 10.10.64.40
 > <nothing>
 > 

It's normal.

 > The fxp driver appears to send something on startup and nothing on 
 > shutdown:
 > 
 > FXP# ifconfig fxp0 inet alias 10.10.64.40
 > 18:41:54.584059 arp who-has 10.10.64.40 tell 10.10.64.40
 > FXP# ifconfig fxp0 inet -alias 10.10.64.40
 > <nothing>
 > 
 > When I manually arping the em alias after startup (i.e. simulate what 
 > fxp does), everything works as expected:
 > 
 > EM# ifconfig em1 inet alias 10.10.64.40
 > <nothing>
 > EM# arping -c1 -S10.10.64.40 10.10.64.40
 > 18:46:07.808701 arp who-has 10.10.64.40 tell 10.10.64.40

Because arping requested it em(4) generated it.

 > EM# ifconfig em1 inet -alias 10.10.64.40
 > <nothing>
 > 
 > It appears that this is what the em driver is supposed to do, or at 
 > least fxp does it in this way.
 > 

No, it's an em(4) driver bug. fxp(4)'s behavior is correct.

 > >This is other issue. em(4) performs two time-consuming operations
 > >in its initialization routine. One is DMA tag/map creation and the
 > >other is checksumming EEPROM contents in init routine.
 > >I have an experimental patch for it but let's fix one at a time.
 > >
 > OK, let's put that aside for now.
 > 
 > Regards,
 > Atanas
 > 

-- 
Regards,
Pyun YongHyeon