Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
   Compare ISP   Rate your ISP
   Glossary   Glossary
Please login or register.

Login with username, password and session length
Advanced search  


Pages: 1 [2]

Author Topic: IPV6 6to4 MTU tunnel setting on Asus router  (Read 1203 times)


  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 32345
  • Over the Rainbow Bridge
    • The ELRepo Project
Re: IPV6 6to4 MTU tunnel setting on Asus router
« Reply #15 on: April 03, 2020, 11:10:34 PM »

So do I add 28 for optimal tunnel size which would be 1452, oh my that's what Weaver said lol

It looks that way and, yes, so he did!  :D
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.


  • Addicted Kitizen
  • *****
  • Posts: 9741
  • Retd sw dev; A&A; 4 ◊ 7km ADSL2; IPv6; Firebrick
Re: IPV6 6to4 MTU tunnel setting on Asus router
« Reply #16 on: April 05, 2020, 06:51:41 AM »

 :-[ I must be going mad. When I said 40 bytes back their I should have said 20. My apologies

An IPv4 proto 41 tunnel, used to encapsulate IPv6, adds an IPv4 header to the start of an IPv6 packet. The IPv4 header is 20 bytes, so the tunnel payload, the IPv6 PDU, will have an MTU that is reduced by 20 bytes compared with the normal IPv6 PDU MTU.

So given my stupidity, I donít have an explanation for the numbers youíre getting. You do indeed add on 28, as you said,
« Last Edit: April 05, 2020, 07:18:19 AM by Weaver »
Pages: 1 [2]