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Bridged modem and rp-pppoe

Posted: Mon Jun 02, 2014 9:42 pm
by maestro
Does anyone else connect to Exetel using a modem in bridged mode?

I am having issues occasionally when the ppp link drops and automatically reconnects. Sometimes the Exetel systems don't respond to PADI packets.

I have tried the following to get the link to work again, none of which worked...
- disconnecting and reconnecting the modem, causing a re-sync.
- rebooting the modem
- restarting the pppoe client
- rebooting the computer that pppoe runs on

I have managed to clear the problem (until next time) by doing the following.
- Disconnecting the bridged modem and connecting a modem configured for PPP
- Letting the second modem sync, and leaving it connected for 5 minutes
- Disconnecting the second modem and reconnecting the first modem.
- The pppoe connection automatically resumes once the first modem syncs again.

I have looked at the PADI packets before and after the 'fix', and there is no difference except for the "Host-Uniq" field.

Has anyone else seen this issue?

Is there anything I can do to get a response to the rp-pppoe PADI packets (any settings in rp-pppoe, maybe)?

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 9:19 am
by maestro
OK, it's happened again. I can see the PADI packets going out to exetel (and can see the outgoing frame counter on my modem showing that they are being sent) but I am receiving nothing back.

Rather than trying my temporary fix, I have left the problem as-is and I am hoping that someone from Exetel can have a look at my port and tell me what is wrong.

Can someone please let me know why I am getting no responses to my PADIs?


Thanks

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 9:35 am
by Dazzled
I dunno about your problem, so can't be much help, but I have in the past used the pppd daemon and pppoeconf to do this job. If I connect directly now I use Network Manager on a desktop, also hassle-free.

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 11:01 am
by maestro
Dazzled wrote:I dunno about your problem, so can't be much help, but I have in the past used the pppd daemon and pppoeconf to do this job. If I connect directly now I use Network Manager on a desktop, also hassle-free.
I used pppoe-setup to configure my link (it comes as part of the rp-pppoe rpm), and I have manually reviewed the generated configuration file after reading the man page and the results of google searches.

I had major issues with Network Manager a while back and had to disable it. Are you able to post any of the config files that Network Manager creates so that I can compare them with mine? (I can post my config tonight - I can't get to it now as my link is not working due to this issue).

I still think that there's something funny going on at Exetel's end, as temporarily plugging in a different modem can reset the fault, and I can then go back to my normal setup without changing anything on my server or modem (or even rebooting or restarting anything) and it just works again. I am hoping that someone can tell me why my PADI packets are being ignored and if there is anything I can change in my config that will stop this from occurring, or be able to reset the problem, without manual intervention.


Thanks

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 2:12 pm
by Dazzled
I went back to a (very) old box that doesn't have network manager. The peer file there was:
noipdefault
defaultroute
replacedefaultroute
hide-password
noauth
persist
plugin rp-pppoe.so eth3
user "xxxxxx"
usepeerdns
This was for pon/poff usage. I don't remember altering the /network/interfaces file for ifup.

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 9:28 pm
by maestro
OK, I have no "peers" file. this is from /etc/sysconfig/network-scripts/ifcfg-ppp0

USERCTL=no
BOOTPROTO=dialup
NAME=DSLppp0
DEVICE=ppp0
TYPE=xDSL
ONBOOT=yes
PIDFILE=/var/run/pppoe-adsl.pid
FIREWALL=NONE
PING=.
PPPOE_TIMEOUT=80
LCP_FAILURE=3
LCP_INTERVAL=20
CLAMPMSS=1412
CONNECT_POLL=6
CONNECT_TIMEOUT=60
DEFROUTE=yes
SYNCHRONOUS=no
ETH=eth3
PROVIDER=DSLppp0
USER=0123456789@nsw.exetel.com.au
PEERDNS=no
DEMAND=no

Re: Bridged modem and rp-pppoe

Posted: Thu Jun 05, 2014 10:00 pm
by maestro
OK, I have tried a few more things...

I tried changing the MAC address on my server, and rebooted the modem... No good.

I reconfigured the modem from bridge mode to PPPoE mode (without changing modems) and it didn't fix the problem, but then I changed it to PPPoA mode and it started working. I was then able to configure the modem for PPPoE mode and it worked, and then configuring back to bridge mode and my server was then able to connect.

So for some reason the Exetel end's PPPoE server has locked me out, but the PPPoA server is still accepting connections.

Does anyone have any idea why?

Could it be CRC errors on the link (I have a bad line which may have more errors than usual)?