Re: Long round trip times on local net

[raymond.meyer%rambler.ru@localhost]

On Wed, 11 Feb 2009 20:04:01 -0500
"Steven M. Bellovin" <smb%cs.columbia.edu@localhost> wrote:

> On Thu, 12 Feb 2009 00:50:50 +0000
> raymond.meyer%rambler.ru@localhost wrote:
> 
> > I have two machines running NetBSD-5 beta, i386 and sparc64. Both
> > machines are on a local network. When I ping i386 machine from
> > sparc64 I notice the following output:
> > 
> > 64 bytes from 192.168.0.40: icmp_seq=49 ttl=255 time=0.261 ms
> > 64 bytes from 192.168.0.40: icmp_seq=50 ttl=255 time=0.254 ms
> > 64 bytes from 192.168.0.40: icmp_seq=51 ttl=255 time=1000.276 ms
> > 64 bytes from 192.168.0.40: icmp_seq=52 ttl=255 time=0.416 ms
> > 64 bytes from 192.168.0.40: icmp_seq=53 ttl=255 time=0.258 ms
> > 64 bytes from 192.168.0.40: icmp_seq=54 ttl=255 time=1000.250 ms
> > 64 bytes from 192.168.0.40: icmp_seq=55 ttl=255 time=0.391 ms
> > 64 bytes from 192.168.0.40: icmp_seq=56 ttl=255 time=0.256 ms
> > 64 bytes from 192.168.0.40: icmp_seq=57 ttl=255 time=0.264 ms
> > 64 bytes from 192.168.0.40: icmp_seq=58 ttl=255 time=0.275 ms
> > 64 bytes from 192.168.0.40: icmp_seq=59 ttl=255 time=0.257 ms
> > 64 bytes from 192.168.0.40: icmp_seq=60 ttl=255 time=1000.249 ms
> > 64 bytes from 192.168.0.40: icmp_seq=61 ttl=255 time=0.386 ms
> > 64 bytes from 192.168.0.40: icmp_seq=62 ttl=255 time=0.264 ms
> > 64 bytes from 192.168.0.40: icmp_seq=63 ttl=255 time=1000.248 ms
> > 64 bytes from 192.168.0.40: icmp_seq=64 ttl=255 time=0.388 ms
> > 
> > Quite a few packets show round trip time of just over a second. If I
> > ping sparc64 machine from i386, the round trip time for all packets is
> > about 0.200 ms, i.e. there are absolutely no over 1 second delays.
> > 
> > Does anyhone know why so many packets have such long delays? The i386
> > has a PCI network card that uses rtk driver, sparc64 uses hme driver.
> > I've tried different CAT cables on both machines, which didn't make
> > any difference. Can this be a hardware problem or a driver bug?
> > 
> Are you doing 'ping' or 'ping -n'?  I wonder if it's a DNS lookup issue
> -- those figures are very suggestive of a 1-second timeout.
> 
> Hmm -- I wonder if an interrupt is getting lost.  That 1 second is the
> interval to the next ping, after all.  Try it with '-i 5' and see if
> you get 5-second delays.  Try it with another transmission (say, via
> ttcp) running in the background and see if that gets rid of the delays.
> 
> 
>               --Steve Bellovin, http://www.cs.columbia.edu/~smb

OK here is what I have so far:

My sparc64 machine is Ultra 10, it has 1 onboard ethernet port and a
Sun quad PCI ethernet card with 4 ethernet ports.

If I do my networking via quad PCI ethernet card, I have problems with
long round trip times as detailed above. I also posted about having
problems with slow NFS

http://mail-index.netbsd.org/netbsd-users/2009/01/27/msg002768.html

Which I now think is related to this issue.

If I do my networking via the onboard ethernet port, everything works
fine, including NFS!

So has anyone with similar Sun hardware noticed these problems? Is it a
hardware problem with the quad PCI card or a buggy driver?