kern/135222: [igb] low speed routing between two igb interfaces

Mishustin Andrew 1 at
Wed Jun 3 18:30:02 UTC 2009

>Number:         135222
>Category:       kern
>Synopsis:       [igb] low speed routing between two igb interfaces
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Jun 03 18:30:01 UTC 2009
>Originator:     Mishustin Andrew
>Release:        FreeBSD 7.1-RELEASE amd64, FreeBSD 7.2-RELEASE amd64
FreeBSD test.hnt 7.2-RELEASE FreeBSD 7.2-RELEASE #12: Thu Apr 30 18:28:15 MSD 20
09     admin at test.hnt:/usr/src/sys/amd64/compile/GENERIC  amd64
I made a FreeBSD multiprocesor server to act as simple gateway.
It use onboard Intel 82575EB Dual-Port Gigabit Ethernet Controller.
I observe traffic speed near 400 Kbit/s.
I test both interfaces separately -
ftp client work at speed near 1 Gbit/s in both directions.
Then I change NIC to old Intel "em" NIC - gateway work at speed near 1 Gbit/s.

Looks like a bug in igb driver have an effect upon forwarded traffic.

If you try
The speed is near 1 Mbit/s

hw.igb.rxd, hw.igb.txd, "ifconfig -tso" has no effect.

Nothing in messages.log

netstat -m
516/1674/2190 mbufs in use (current/cache/total)
515/927/1442/66560 mbuf clusters in use (current/cache/total/max)
515/893 mbuf+clusters out of packet secondary zone in use (current/cache)
0/44/44/33280 4k (page size) jumbo clusters in use (current/cache/total/max)
0/0/0/16640 9k jumbo clusters in use (current/cache/total/max)
0/0/0/8320 16k jumbo clusters in use (current/cache/total/max)
1159K/2448K/3607K bytes allocated to network (current/cache/total)
0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
0/0/0 requests for jumbo clusters denied (4k/9k/16k)
0/0/0 sfbufs in use (current/peak/max)
0 requests for sfbufs denied
0 requests for sfbufs delayed
0 requests for I/O initiated by sendfile
0 calls to protocol drain routines

I use only IPv4 traffic.

On machine with two igb interfaces
use rc.conf like this:


And try create heavy traffic between two networks.


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