Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Andrews and Arnold AAISP L2TP with DSL Backup  (Read 1243 times)

aesmith

  • Kitizen
  • ****
  • Posts: 1255
Andrews and Arnold AAISP L2TP with DSL Backup
« on: September 30, 2024, 04:52:22 PM »

I realise this might be an unusual idea, but I'm considering using by AA L2TP account over Starlink for normal operation, to get around CGNAT issues. However I'm keeping my AA ADSL for the meantime, as failover if Starlink goes down. Anyone do anything similar? I think I would need to configure things so in a failover situation it doesn't try to connect to L2TP over the ADSL, which I presume would fail.
Logged

Alex Atkin UK

  • Addicted Kitizen
  • *****
  • Posts: 5464
    • Thinkbroadband Quality Monitors
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #1 on: September 30, 2024, 05:53:05 PM »

Not really unusual, its the exact reason they sell the L2TP as standalone if you don't have them as your ISP.

The problematic part is if you are using your ADSL L2TP connection, you can't be connected to ADSL and L2TP at the same time.  You'd need to either make sure PPP is only brought up on ADSL when Starlink is down, or pay for a second L2TP connection.
Logged
Broadband: Zen Full Fibre 900 + Three 5G Routers: pfSense (Intel N100) + GL.iNet GL-X3000/ Spitz AX WiFi: Zyxel NWA210AX
Switches: Netgear MS510TXUP, Netgear MS510TXPP, Netgear GS110EMX My Broadband History & Ping Monitors

aesmith

  • Kitizen
  • ****
  • Posts: 1255
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #2 on: September 30, 2024, 06:11:20 PM »

Cheers. In testing what seems to happen is that L2TP takes priority at the routing level. When it's up the ADSL stays up, but any traffic either gets binned at AA, or maybe return traffic does. Either way traceroute shows just one hop after my router. As soon as I disable the L2TP then routing via ADSL immediately resumes, no retrain or anything needed.

But that was a short test, I dont know whether leaving L2TP up would cause the ADSL to drop PPP at some point.
Logged

Chrysalis

  • Content Team
  • Addicted Kitizen
  • *
  • Posts: 7491
  • AAISP CF
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #3 on: September 30, 2024, 07:51:21 PM »

As far as I know if you have a broadband account with AAISP, it can also be used as L2TP, so if you are prepared to keep the ADSL disconnected (not the sync just the PPP auth) whilst the Starlink is online you can save a bit of money.

Then when the starlink goes down, login to the ADSL using the same details.
Logged

aesmith

  • Kitizen
  • ****
  • Posts: 1255
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #4 on: September 30, 2024, 09:12:51 PM »

I need to test a bit more but at the moment it seems like ADSL can stay up, with PPP logged in, even while I am logged into L2TP. It just doesn't route. Then when L2TP drops it immediately starts routing with no intervention needed.

I need to test whether it stays "waiting" like that indefinitely, and also whether it will restart after a retrain or power cut and resume "waiting".

But also need to find some way of stopping the L2TP trying (or succeeding) to reestablish over the ADSL when Internet fails over.
Logged

Alex Atkin UK

  • Addicted Kitizen
  • *****
  • Posts: 5464
    • Thinkbroadband Quality Monitors
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #5 on: October 01, 2024, 03:01:57 AM »

I need to test a bit more but at the moment it seems like ADSL can stay up, with PPP logged in, even while I am logged into L2TP. It just doesn't route. Then when L2TP drops it immediately starts routing with no intervention needed.

Its very smart if AAISP has implemented it so L2TP always takes priority.  Having the end users router in control (by simply dropped L2TP if the main connection is working) is a very graceful way of doing it.
Logged
Broadband: Zen Full Fibre 900 + Three 5G Routers: pfSense (Intel N100) + GL.iNet GL-X3000/ Spitz AX WiFi: Zyxel NWA210AX
Switches: Netgear MS510TXUP, Netgear MS510TXPP, Netgear GS110EMX My Broadband History & Ping Monitors

aesmith

  • Kitizen
  • ****
  • Posts: 1255
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #6 on: October 01, 2024, 09:12:06 AM »

I'm missing the obvious. I'll just ask Andrews and Arnold whether this is expected behaviour and can therefore be relied on. I'll do a few quick tests first, for example rebooting the ADSL.
Logged

Chrysalis

  • Content Team
  • Addicted Kitizen
  • *
  • Posts: 7491
  • AAISP CF
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #7 on: October 04, 2024, 06:36:40 AM »

Please let us know how they respond, as I am curious also. :)
Logged

aesmith

  • Kitizen
  • ****
  • Posts: 1255
Re: Andrews and Arnold AAISP L2TP with DSL Backup
« Reply #8 on: October 11, 2024, 03:46:46 PM »

Not yet asked A&A as there are some more tests I want to carry out first. For example failover by blocking L2TP and letting it fail of its own according, that might behave differently than my tests shutting down L2TP manually. But that sort of test needs a longer period of downtime and whenever I remember it never seems to be  good time.

But one thing I have noticed is that if DSL retains then when it connects AA sometimes apply the DSL speed to the L2TP connection. Not always, but for example the DSL always drops for 11 minutes just after midnight GMT, and the profile is applied ..

Today 00:11:21 Tx rate (adjusted) 98000000 to 3953582 (rx 828000) -RADIUS-
Today 00:11:21 Deferred KCI email 2024-10-11 00:11:19 DSL line up (down 11 minutes) KCI


But when I've tested retrain myself it doesn't necessarily do the same. And to add further uncertainty even when that rate IS applied, it doesn't always affect my speed over LT2P.

I can work around th midnight drop by scheduling something to disable and then re-enable the L2TP in the small  hours.
Logged