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Look at logs, if you see something like

[2012-01-18|09:06:02]: warn: l2tp: incorrect tid 0 in tunnel 4

then you can solve it by adding following option to config


Zyxel doesn't connect by l2tp

Look at logs, if you see something like

[2012-01-18|09:16:02]: warn: l2tp: incorrect avp received (type=7, M=0, must be 1)

its because zyxel's client doesn't conform rfc:

      The Host Name AVP, Attribute Type 7, indicates the name of the
      issuing LAC or LNS.

      This name should be as broadly unique as possible; for hosts
      participating in DNS [RFC1034], a hostname with fully qualified
      domain would be appropriate.

      This AVP MUST NOT be hidden (the H-bit MUST be 0). The M-bit for
      this AVP MUST be set to 1.  The Length of this AVP is 6 plus the
      length of the Host Name.

Anyway you can solve it by modifying accel-ppp's l2tp dictionary:

  1. open install_prefix/share/accel-ppp/l2tp/dictionary.rfc2661

2. find line ATTRIBUTE Host-Name 7 string M=1 3. clear M=1 4. save file and restart accel-ppp If it still doesn't connect search the log for messages like warn: l2tp: incorrect avp received (type=7, M=0, must be 1), its maybe other attributes are incorrect too so you can modify l2tp dictionary for it.

Built-in shaper doesn't provide required rates

First of all look at qdisc/filter parameters on interface, typical commands are:

tc qdisc show dev pppX
tc filter show dev pppX parent ffff:

If parameters are matched to required then it is not accel-ppp's problem. You can try following: look at offload settings on your network cards:

$ ethtool -k eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: off
scatter-gather: off
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: off
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: on
tx-vlan-offload: on
ntuple-filters: off
receive-hashing: off

and turn off all offload parameters except checksumming and scatter-gatter.

knownissues.txt · Last modified: 2014/10/12 16:48 by dmitry