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sukram
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PPPoE Client: Where to find PPPoE Auth-Ack Message

Sun Jan 21, 2024 12:20 am

Hello there,

is there any way to read the Contents of the Auth-Ack Message from a PPPoE Connection?

I am running a RB4011 with a Zyxel VDSL Modem. My Provider, on succsessfull Authentication, answers with a Message containing the actual trafficshaper Limits on his side (based on what Sync the MSAN is reporting).

The format of the Message would be like this:
Message='SRU=yyyy#SRD=xxxx#'
Where can i find this to setup appropriate values on my Connection? I tried with Sniffing on the Connection and i can see the Message incoming, but do not find where this data is hidden in Terminal or Winbox.

Thanks in advance!

MfG Markus
 
matd
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Re: PPPoE Client: Where to find PPPoE Auth-Ack Message

Sun Jan 21, 2024 2:33 pm

Hi,
save the packet sniff into file, then copy pcap file from flash to PC and open in Wireshark.
 
sukram
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Re: PPPoE Client: Where to find PPPoE Auth-Ack Message

Sun Jan 21, 2024 2:38 pm

Hi,
save the packet sniff into file, then copy pcap file from flash to PC and open in Wireshark.
Hello,

thanks. I already know this way, but i was curios if there is any "out-of-the-box" functionality to retrieve this information for scripting. I don't want to rely on a script to telnet into the modem and take the data from there, when all i need is already in the router.
Last edited by sukram on Sun Jan 21, 2024 2:39 pm, edited 1 time in total.
 
rplant
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Re: PPPoE Client: Where to find PPPoE Auth-Ack Message

Mon Jan 22, 2024 12:23 pm

If you are using tools/packet sniffer.
You can click on packets, choose the appropriate one, and look at the raw hex data in winbox

You can also go into system\logging
Add a new rule with topics pppoe and action = memory
And see if the required information arrives in the log.

Slightly offtopic

With pppoe clients I find it useful to add another action to the logging
(I call it memory2) of type memory with a 100 or so lines.

Then change the default info Rule -> info, !pppoe
And add pppoe, !debug and use the memory2 action for it.

Otherwise a broken pppoe connection (server not answering, etc) will rapidly fill up the log with pppoe messages.
Losing all other logging.
 
sukram
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Re: PPPoE Client: Where to find PPPoE Auth-Ack Message

Tue Jan 23, 2024 1:15 am

Thank you, this bings me a small step forward.

I followed your Trick with separate log memory. With debug output enabled, i can see the Message being logged:
Screenshot 2024-01-22 212340.png
Now, i am digging through scripting to extract this, but this will take some time. Many examples of "new line in log scripts" fail when memory log keeps rolling over.
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rplant
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Re: PPPoE Client: Where to find PPPoE Auth-Ack Message

Tue Jan 23, 2024 5:22 am

perhaps change the buffer size in memory2 to be a 1000 or more lines, or with appropriate scripting stop on full.

It looks to be part of ppp, so you could do ppp, debug, packet instead might reduce the amount of data slightly.