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IDProjectCategoryView StatusDate SubmittedLast Update
0020251ClearOSapp-network - Network Settingspublic2018-05-29 06:252018-05-29 14:06
ReporterNickH 
Assigned To 
PrioritynormalSeverityfeatureReproducibilityhave not tried
StatusconfirmedResolutionopen 
PlatformOSOS Version
Product Version7.4.0 
Target Version7.5.0 UpdatesFixed in Version 
Summary0020251: Use kernel mode PPPoE rather than User mode
DescriptionUser mode PPPoE uses considerably more resources and appears to restrict the speed of PPPoE connections more than kernel mode. As an example, on a Core-i5 machine, the ppp0 process consumed 35% CPU while limiting connection speeds to about 290Mbps on a 1000Mbps connection. Switching to Kernel Mode increased the speed to c. 790Mbps and CPU usage was not noticeable (did not appear in "top").

These days 1000Mbps connections are becoming more common and ClearOS is restricting their use.

All that is needed to enable Kernel Mode support is to add a line:
LINUX_PLUGIN=/usr/lib64/pppd/2.4.5/rp-pppoe.so
to:
/etc/sysconfig/network-scripts/ifcfg-pppX

It could either be done for all pppX interfaces or by a preference.

Going back in time, Kernel Mode PPPoE was developed during the 2.2/2.3 kernels and was released mainstream in 2.4 so it is well tried and tested. There is more information in the rp-pppoe sources.
References:
https://www.usenix.org/legacy/publications/library/proceedings/als00/2000papers/papers/full_papers/skoll/skoll_html/index.html [^] (old but gives history)
http://openbsd-archive.7691.n7.nabble.com/advantages-disadvantages-of-kernel-pppoe-4-vs-userland-pppoe-8-td13288.html [^] (pros and cons)
Clearcenter ticket 558584
TagsNo tags attached.
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-  Notes
(0007511)
NickH (developer)
2018-05-29 14:06

From https://www.linuxquestions.org/questions/blog/kostya-519950/pppoe-roaring-penguin-vs-kernel-pppoe-issues-and-solutions-3565/ [^] and Ben's testing it needs a firewall rule:
iptables -t mangle -I FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

Also from the same article it looks like the plugin can be invoked from /etc/ppp/options
with a line:
plugin rp-pppoe.so

- Issue History
Date Modified Username Field Change
2018-05-29 06:25 NickH New Issue
2018-05-29 13:26 pbaldwin Status new => confirmed
2018-05-29 13:27 pbaldwin Target Version => 7.5.0 Updates
2018-05-29 14:06 NickH Note Added: 0007511