Bug 236486 - [igb] txcsum produces broken checksum for i350
Summary: [igb] txcsum produces broken checksum for i350
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 11.2-STABLE
Hardware: amd64 Any
: --- Affects Some People
Assignee: freebsd-net mailing list
URL:
Keywords: IntelNetworking
Depends on:
Blocks:
 
Reported: 2019-03-12 13:48 UTC by Eugene Grosbein
Modified: 2019-03-12 13:49 UTC (History)
0 users

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Description Eugene Grosbein freebsd_committer 2019-03-12 13:48:32 UTC
Hi!

The server Dell PowerEdge R640 (baseboard 0PHYDR) with BIOS Version: 1.6.13 02/13/2019 [Hetzner 1.0.2] has Intel 1GB i350 network card:

igb0@pci0:1:0:0:        class=0x020000 card=0x1f9a1028 chip=0x15218086 rev=0x01 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'I350 Gigabit Network Connection'
    class      = network
    subclass   = ethernet

It runs FreeBSD 11.2-STABLE/amd64 r344922 with GENERIC kernel config plus following options only:

options KDB
options KDB_UNATTENDED
options KDB_TRACE
options DDB
options GDB

It also runs ipfw nat that is not compatible with TSO4 so this option is disabled for igb0. Still, running with tso4 disabled and txcsum enabled, it suffers from stalled TCP connections due to some TCP segments being sent with broken checksum occasionally.

ifconfig igb0 -txcsum solves the problem.