MTU can't be higher than 4096

Bug #1430993 reported by Bryan Quigley
16
This bug affects 2 people
Affects Status Importance Assigned to Milestone
ifupdown (Ubuntu)
Invalid
Medium
Unassigned

Bug Description

Using a KVM virtual machine with 12 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 20).

Simple config:
# The primary network interface
auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet static
 address 192.168.200.128
 netmask 255.255.255.0
 mtu 4097

While mtu of 4096 comes up fine.

Mar 11 15:50:38 networkbase systemd[1]: Started User Manager for UID 1000.
Mar 11 15:50:38 networkbase kernel: ifquery[914]: segfault at 0 ip 00000000004031c8 sp 00007ffc6057d870 error 4 in ifup[400000+d000]
Mar 11 15:50:38 networkbase sh[777]: Segmentation fault (core dumped)
.... Repeats a lot.....
Mar 11 15:52:28 networkbase kernel: ifquery[1524]: segfault at 0 ip 00000000004031c8 sp 00007fffd0121230 error 4 in ifup[400000+d000]
Mar 11 15:52:28 networkbase sh[777]: Segmentation fault (core dumped)
Mar 11 15:52:29 networkbase systemd[1]: ifup-wait-all-auto.service start operation timed out. Terminating.
Mar 11 15:52:29 networkbase systemd[1]: Failed to start Wait for all "auto" /etc/network/interfaces to be up for network-online.target.
Mar 11 15:52:29 networkbase systemd[1]: Unit ifup-wait-all-auto.service entered failed state.
Mar 11 15:52:29 networkbase systemd[1]: ifup-wait-all-auto.service failed.
Mar 11 15:52:29 networkbase systemd[1]: Reached target Network is Online.

ProblemType: Crash
DistroRelease: Ubuntu 15.04
Package: ifupdown 0.7.48.1ubuntu6
ProcVersionSignature: Ubuntu 3.19.0-8.8-generic 3.19.1
Uname: Linux 3.19.0-8-generic x86_64
ApportVersion: 2.16.2-0ubuntu2
Architecture: amd64
Date: Wed Mar 11 15:46:11 2015
ExecutablePath: /sbin/ifup
InstallationDate: Installed on 2015-03-04 (6 days ago)
InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Alpha amd64 (20150304)
ProcCmdline: ifquery --state eth0 eth1
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
SegvAnalysis: Skipped: missing required field "Disassembly"
Signal: 11
SourcePackage: ifupdown
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

Revision history for this message
Bryan Quigley (bryanquigley) wrote :
Revision history for this message
Apport retracing service (apport) wrote :

StacktraceTop: main (argc=4, argv=0x7fca7df3f7b8 <main_arena+88>) at main.c:591

Revision history for this message
Apport retracing service (apport) wrote : Stacktrace.txt
Revision history for this message
Apport retracing service (apport) wrote : StacktraceSource.txt
Revision history for this message
Apport retracing service (apport) wrote : ThreadStacktrace.txt
Changed in ifupdown (Ubuntu):
importance: Undecided → Medium
tags: removed: need-amd64-retrace
Revision history for this message
Bryan Quigley (bryanquigley) wrote :

The driver/hardware for rtl8139 seems to be limited at 4096:
bryan@desktop:/mnt/store/git/linux-git/drivers/net/ethernet/realtek$ grep 4096 *
8139cp.c:#define CP_MAX_MTU 4096
8139cp.c: RxErrLong = (1 << 21), /* Rx error, packet > 4096 bytes */

I wonder if ifupdown can handle this better and report that the MTU is to high.. maybe even fallback to maximum and note it in the logs?

Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in ifupdown (Ubuntu):
status: New → Confirmed
Revision history for this message
Bryan Quigley (bryanquigley) wrote :

ifupdown isn't recommended anymore, so closing this.

Changed in ifupdown (Ubuntu):
status: Confirmed → Invalid
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