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    PPPoE packet loss problem (MTU?)

    Scheduled Pinned Locked Moved General pfSense Questions
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    • C
      clarknova
      last edited by

      I'm trying to diagnose and sort out an mtu problem with my multilink PPPoE connection and could use some assistance.

      My pppoe interface is a 6-line MLPPP connection. Certain SSL web sites won't load completely and I suspected an MTU problem, so I did some testing.

      When ping from pfsense to the upstream gateway, any payload size (-s) less than 1425 elicits a response, while any payload greater than 1424 times out (with no response appearing on tcpdump -i pppoe0 either).

      I tried setting the mtu of pppoe0 to 1452 (using ifconfig in the shell). I tried setting the MTU and MRU of the member interfaces to 1452 (PPPs page in the GUI). None of these changes changed the result that no echo request packet larger than 1452 elicits a response from the ISP's gateway router.

      No doubt I have configured something wrong due to a lack of understanding of PPP or MTU, but I'm not sure what to do about it, and I would appreciate some guidance.

      My /var/etc/mpd_wan.conf file for reference:

      
      startup:
              # configure the console
              set console close
              # configure the web server
              set web close
      
      default:
      pppoeclient:
              create bundle static wan
              set iface name pppoe0
              set iface route default
              set iface disable on-demand
              set iface idle 0
              set iface enable tcpmssfix
              set iface up-script /usr/local/sbin/ppp-linkup
              set iface down-script /usr/local/sbin/ppp-linkdown
              set ipcp ranges 0.0.0.0/0 0.0.0.0/0
              #log -bund -ccp -chat -iface -ipcp -lcp -link
      
              create link static wan_link0 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan201
              open
      
              create link static wan_link1 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan202
              open
      
              create link static wan_link2 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan203
              open
      
              create link static wan_link3 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan205
              open
      
              create link static wan_link4 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan206
              open
      
              create link static wan_link5 pppoe
              set link action bundle wan
              set link enable multilink
              set link keep-alive 10 60
              set link max-redial 0
              set link disable chap pap
              set link accept chap pap eap
              set link disable incoming
              set link mtu 1452
              set link mru 1452
              set auth authname "username@teksavvy.com"
              set auth password secret
              set pppoe service ""
              set pppoe iface em0_vlan207
              open
      
      

      db

      1 Reply Last reply Reply Quote 0
      • chpalmerC
        chpalmer
        last edited by

        Verify with your ISP that "ppp multilink fragment disable" is turned off on their end.

        Triggering snowflakes one by one..
        Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

        1 Reply Last reply Reply Quote 0
        • C
          clarknova
          last edited by

          Thank you for the suggestion. I have inquired and will post back updates.

          db

          1 Reply Last reply Reply Quote 0
          • chpalmerC
            chpalmer
            last edited by

            clarknova- any progress??

            Triggering snowflakes one by one..
            Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

            1 Reply Last reply Reply Quote 0
            • C
              clarknova
              last edited by

              I had "Disable Firewall Scrub" checked. Unchecking this fixed the problem. I'm a little embarrassed, as I really thought that I had tried this already. Thanks for the responses.

              db

              1 Reply Last reply Reply Quote 0
              • chpalmerC
                chpalmer
                last edited by

                Cool- good to see its working for you!

                Now I need to go loiok at my setup and see if I have that checked or not…

                :)

                Triggering snowflakes one by one..
                Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

                1 Reply Last reply Reply Quote 0
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