Why would adsl setup change from ppoa to ppoe?

Just came across a Tesco.net adsl (not llu) account. Account functioned for
years on a zyxel router with standard settings PPOA, vc mux 0 38, with adsl
user name and password.

Over the last few days connection was lost (indicated by red light on
router), adsl sync maintained, but unable to authenticate. Tried a different
router, same issue.

Decided to try PPOE, LLC 0 38 on the alternative router, it worked straight
away, changed original router to these settings also worked.

Can anyone think of a reason why such a thing would happen?

Tired wrote:
> Just came across a Tesco.net adsl (not llu) account. Account functioned for
> years on a zyxel router with standard settings PPOA, vc mux 0 38, with adsl
> user name and password.
>
> Over the last few days connection was lost (indicated by red light on
> router), adsl sync maintained, but unable to authenticate. Tried a different
> router, same issue.
>
> Decided to try PPOE, LLC 0 38 on the alternative router, it worked straight
> away, changed original router to these settings also worked.
>
> Can anyone think of a reason why such a thing would happen?
>
>
some eejit screwed something up somewhere?

Far as I know all backhaul is currently ATM and thats the normal
termination at the ISP...

On Wed, 2011-10-12 at 01:25 +0100, The Natural Philosopher wrote:
> Far as I know all backhaul is currently ATM and thats the normal
> termination at the ISP...

It's still ATM. When we talk of 'PPPoE' we actually mean 'PPPoEoA'. Your
PPP frames are encapsulated in Ethernet frames and then those Ethernet
frames are transported over ATM according to RFC2684.

These days, it *isn't* necessarily ATM all the way to the ISP. It tends
to be an L2TP link instead. But still, it's surprising that the OP can
no longer switch arbitrarily between PPPoEoA and PPPoA at his end.

I would definitely report this as a fault and try to get it fixed.
PPPoEoA is less efficient and gives you a smaller MTU. And since there
are a lot of stupid people out there who like to firewall ICMP, an MTU
lower than 1500 can cause problems in some cases.

--
dwmw2

On 11/10/2011 22:33, Tired wrote:
> Just came across a Tesco.net adsl (not llu) account. Account functioned for
> years on a zyxel router with standard settings PPOA, vc mux 0 38, with adsl
> user name and password.
>
> Over the last few days connection was lost (indicated by red light on
> router), adsl sync maintained, but unable to authenticate. Tried a different
> router, same issue.
>
> Decided to try PPOE, LLC 0 38 on the alternative router, it worked straight
> away, changed original router to these settings also worked.
>
> Can anyone think of a reason why such a thing would happen?
>
>

When I installed a new router, it auto-configured for
PPPoE and worked OK. I changed to the recommended
PPPoA, but it didn't appear to make any obvious
difference. Maybe the latest exchange equipment
doesn't care.

On 12/10/11 11:28, Jim wrote:
> On 11/10/2011 22:33, Tired wrote:
>> Just came across a Tesco.net adsl (not llu) account. Account
>> functioned for
>> years on a zyxel router with standard settings PPOA, vc mux 0 38, with
>> adsl
>> user name and password.
>>
>> Over the last few days connection was lost (indicated by red light on
>> router), adsl sync maintained, but unable to authenticate. Tried a
>> different
>> router, same issue.
>>
>> Decided to try PPOE, LLC 0 38 on the alternative router, it worked
>> straight
>> away, changed original router to these settings also worked.
>>
>> Can anyone think of a reason why such a thing would happen?
>>
>>
>
> When I installed a new router, it auto-configured for PPPoE and worked
> OK. I changed to the recommended PPPoA, but it didn't appear to make
> any obvious difference. Maybe the latest exchange equipment doesn't care.

I think it's been the case for a few years that BT Wholesale ADSL works
with both PPPoE and PPPoA.
Sounds like there's a fault somewhere for the OP if PPPoA has stopped
working. Although it sounds like the link is OK but authentication
has failed, which is strange to affect PPPoA but not PPPoE.

Andrew Benham wrote:
> On 12/10/11 11:28, Jim wrote:
>> On 11/10/2011 22:33, Tired wrote:
>>> Just came across a Tesco.net adsl (not llu) account. Account
>>> functioned for
>>> years on a zyxel router with standard settings PPOA, vc mux 0 38, with
>>> adsl
>>> user name and password.
>>>
>>> Over the last few days connection was lost (indicated by red light on
>>> router), adsl sync maintained, but unable to authenticate. Tried a
>>> different
>>> router, same issue.
>>>
>>> Decided to try PPOE, LLC 0 38 on the alternative router, it worked
>>> straight
>>> away, changed original router to these settings also worked.
>>>
>>> Can anyone think of a reason why such a thing would happen?
>>>
>>>
>> When I installed a new router, it auto-configured for PPPoE and worked
>> OK. I changed to the recommended PPPoA, but it didn't appear to make
>> any obvious difference. Maybe the latest exchange equipment doesn't care.
>
> I think it's been the case for a few years that BT Wholesale ADSL works
> with both PPPoE and PPPoA.
> Sounds like there's a fault somewhere for the OP if PPPoA has stopped
> working. Although it sounds like the link is OK but authentication
> has failed, which is strange to affect PPPoA but not PPPoE.

It may be a packet fragmentation issue.
the whole way the radius authentication works is weird, with BT servers
set up as proxies IIRC, which then pass the auth details over to the
ISP's own servers.

Andrew Benham wrote:
> On 12/10/11 11:28, Jim wrote:
>> On 11/10/2011 22:33, Tired wrote:
>>> Just came across a Tesco.net adsl (not llu) account. Account
>>> functioned for
>>> years on a zyxel router with standard settings PPOA, vc mux 0 38,
>>> with adsl
>>> user name and password.
>>>
>>> Over the last few days connection was lost (indicated by red light
>>> on router), adsl sync maintained, but unable to authenticate. Tried
>>> a different
>>> router, same issue.
>>>
>>> Decided to try PPOE, LLC 0 38 on the alternative router, it worked
>>> straight
>>> away, changed original router to these settings also worked.
>>>
>>> Can anyone think of a reason why such a thing would happen?
>>>
>>>
>>
>> When I installed a new router, it auto-configured for PPPoE and
>> worked OK. I changed to the recommended PPPoA, but it didn't appear
>> to make
>> any obvious difference. Maybe the latest exchange equipment doesn't
>> care.
>
> I think it's been the case for a few years that BT Wholesale ADSL
> works with both PPPoE and PPPoA.
> Sounds like there's a fault somewhere for the OP if PPPoA has stopped
> working. Although it sounds like the link is OK but authentication
> has failed, which is strange to affect PPPoA but not PPPoE.

Thanks for all the responses. The reason i tried this was I have come across
a similar issue with AOL in the past, that for some lines, authentication
would only take place on pppoe.

The line seems to be stable now on the pppoe settings. Trying to explain the
situation to first tier customer support is going to be far more trouble
than it is worth.

Tired wrote:
> Andrew Benham wrote:
>> On 12/10/11 11:28, Jim wrote:
>>> On 11/10/2011 22:33, Tired wrote:
>>>> Just came across a Tesco.net adsl (not llu) account. Account
>>>> functioned for
>>>> years on a zyxel router with standard settings PPOA, vc mux 0 38,
>>>> with adsl
>>>> user name and password.
>>>>
>>>> Over the last few days connection was lost (indicated by red light
>>>> on router), adsl sync maintained, but unable to authenticate. Tried
>>>> a different
>>>> router, same issue.
>>>>
>>>> Decided to try PPOE, LLC 0 38 on the alternative router, it worked
>>>> straight
>>>> away, changed original router to these settings also worked.
>>>>
>>>> Can anyone think of a reason why such a thing would happen?
>>>>
>>>>
>>> When I installed a new router, it auto-configured for PPPoE and
>>> worked OK. I changed to the recommended PPPoA, but it didn't appear
>>> to make
>>> any obvious difference. Maybe the latest exchange equipment doesn't
>>> care.
>> I think it's been the case for a few years that BT Wholesale ADSL
>> works with both PPPoE and PPPoA.
>> Sounds like there's a fault somewhere for the OP if PPPoA has stopped
>> working. Although it sounds like the link is OK but authentication
>> has failed, which is strange to affect PPPoA but not PPPoE.
>
> Thanks for all the responses. The reason i tried this was I have come across
> a similar issue with AOL in the past, that for some lines, authentication
> would only take place on pppoe.
>
> The line seems to be stable now on the pppoe settings. Trying to explain the
> situation to first tier customer support is going to be far more trouble
> than it is worth.
>
>
In general the correct response when having issues with AOL is to get a
Mac code.

The support is completely hopeless.