Junos OS

Expand all | Collapse all

Is MTU clamp mss require for pppoe server?

Jump to Best Answer
  • 1.  Is MTU clamp mss require for pppoe server?

    Posted 06-06-2018 13:17

    for linux i used to create mangle lines with Clamp TCp MSS option to avoid pppoe pmtu problems. Do i need setting something like that for
    juniper mx?

     

    Example of linux rules:

    -A FORWARD -o ppp+ -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1453:65535 -j TCPMSS --set-mss 1452
    -A FORWARD -i ppp+ -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1373:65535 -j TCPMSS --set-mss 1372

     



  • 2.  RE: Is MTU clamp mss require for pppoe server?
    Best Answer

    Posted 06-06-2018 18:38

    Yes, you will need same on MX, but 2 options here 

    1) MPC line card support for inline changing tcp mss for trasit packets see doc here

    2) to change tcp mss for both directions you will need MS-MPC card, same doc 



  • 3.  RE: Is MTU clamp mss require for pppoe server?

    Posted 06-08-2018 05:19


    I configurated here:

    set dynamic-profiles PPPoE-Profile interfaces pp0 unit "$junos-interface-unit" family inet tcp-mss 1452
    set dynamic-profiles PPPoE-Profile interfaces pp0 unit "$junos-interface-unit" family inet6 tcp-mss 1452

    Is that correct for pp0.0 interfaces?

    I think pp0.0 itnerfaces is not gr- (GRE), ge- (Gigabit Ethernet), xe- (10-Gigabit Ethernet), and et- (40-Gigabit and 100-Gigabit Ethernet) but junos don't give any errors.



  • 4.  RE: Is MTU clamp mss require for pppoe server?

    Posted 06-08-2018 09:14

    yes, you can , but in most cases you need to clamp it in both directions



  • 5.  RE: Is MTU clamp mss require for pppoe server?

    Posted 06-08-2018 11:48

    So i'm afraid tha I can't do for MX104/Mx204 routers?