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Feature #10222

Tune GRE MTU if GRE over IPsec is used

Added by Viktor Gurov 9 months ago. Updated 8 months ago.

Status:
Resolved
Priority:
Normal
Category:
Interfaces
Target version:
Start date:
01/30/2020
Due date:
% Done:

100%

Estimated time:

Description

Default GRE MTU value is 1500 (it should be 1476 as maximum for ethernet),
This is impossible in most cases when GRE/IPsec is used

It can be useful to set default MTU value for such cases to 1400
by using such logic:

if ((GRE SOURCE == IPSEC PH1 SOURCE) && (GRE DESTINATION == IPSEC PH2 DESTINATION) &&
    (IPSEC MODE == TRANSPORT) && (IPSEC == ENABLED) && (GRE MTU is not manually entered)) {
            $GRE_MTU = 1400;
}

Associated revisions

Revision b08a1fa1 (diff)
Added by Viktor Gurov 9 months ago

Set correct default MTU for GRE,GIF and GRE/IPsec. Issue #10222

History

#1 Updated by Viktor Gurov 9 months ago

When you first create GRE/GIF interfaces, pfSense sets the correct MTU for it - 1476/1280
But with any change on the interface edit page, it set MTU to 1500
This PR also fixes this

https://github.com/pfsense/pfsense/pull/4177

#2 Updated by Jim Pingle 9 months ago

  • Status changed from New to Pull Request Review

#3 Updated by Renato Botelho 9 months ago

  • Status changed from Pull Request Review to Feedback
  • Assignee set to Renato Botelho
  • Target version set to 2.5.0
  • % Done changed from 0 to 100

PR has been merged. Thanks!

#4 Updated by Viktor Gurov 8 months ago

  • Status changed from Feedback to Resolved

tested on 2.5.0.a.20200219.1144

all three cases (GIF,GRE,GRE/IPsec) works as expected

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