DNS/Proxy server problem?

[Me]

I am getting more and more DNS errors on NTL Freedom dial-up. At times
it takes about 15 connections before I can get a couple of sites in
particular, one of which is my own, (not with NTL). My brother and
brother in law, both on NTL dialup have the same problem with the same
sites. It's annoying as it affects email and ftp access.

The sites all work every time when connected via BT Internet.

I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland. NTL
said delete cookies, clear cache etc which isn't the problem.

Anyone else having similar problems?

[Dave Mason]

On Sat, 19 Feb 2005 16:20:45 GMT, "Me"

Post by Me
I am getting more and more DNS errors on NTL Freedom dial-up. At times
it takes about 15 connections before I can get a couple of sites in
particular, one of which is my own, (not with NTL). My brother and
brother in law, both on NTL dialup have the same problem with the same
sites. It's annoying as it affects email and ftp access.
The sites all work every time when connected via BT Internet.
I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland. NTL
said delete cookies, clear cache etc which isn't the problem.
Anyone else having similar problems?

I did when I was with NTL.

Try http://ntcanuck.com/

[Me]

Post by Dave Mason
On Sat, 19 Feb 2005 16:20:45 GMT, "Me"

Post by Me
I am getting more and more DNS errors on NTL Freedom dial-up. At times
it takes about 15 connections before I can get a couple of sites in
particular, one of which is my own, (not with NTL). My brother and
brother in law, both on NTL dialup have the same problem with the same
sites. It's annoying as it affects email and ftp access.
The sites all work every time when connected via BT Internet.
I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland.

NTL

Post by Dave Mason

Post by Me
said delete cookies, clear cache etc which isn't the problem.
Anyone else having similar problems?

I did when I was with NTL.
Try http://ntcanuck.com/

Cheers

I think I will just cancel my account with NTL and go elsewhere if they
can't fix the problem.

[Me]

Post by Me
I am getting more and more DNS errors on NTL Freedom dial-up. At times
it takes about 15 connections before I can get a couple of sites in
particular, one of which is my own, (not with NTL). My brother and
brother in law, both on NTL dialup have the same problem with the same
sites. It's annoying as it affects email and ftp access.
The sites all work every time when connected via BT Internet.
I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland.

NTL

Post by Me
said delete cookies, clear cache etc which isn't the problem.
Anyone else having similar problems?

On the off chance that any support people read this here is some
information which might help diagnose the problem. I have emailed it to
support as well.

When connected to any of the following NTL IP addresses I get DNS
problems on some sites:

217.137.240.21
217.137.240.23
217.137.240.29
217.137.240.50
217.137.240.52
217.137.240.58
217.137.240.94
217.137.240.98
217.137.240.105
217.137.240.111
217.137.240.117
217.137.240.124

When connected to the following range the sites work fine:

62.252.152.13
62.252.152.34
62.252.152.62

Now I'm no expert but I'm seeing a pattern there. :-) Sadly there seem
to be more connections to the 217.137.240 range than the 62.252.152 range
so it gets very frustrating, reconnecting 20+ plus times just to get a
website or check email.

I'm guessing there is a something up with the configuration of the
217.137.240 servers.

Hope that is useful.

[Rob Chambers]

Post by Me
I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland. NTL
said delete cookies, clear cache etc which isn't the problem.
Anyone else having similar problems?

I have occasionally in the past; it used to be quite common and was
known as the "dead IP problem".

Sticking "ntl dead ip" (without quotes) into Google Groups turns up a
lot of discussions about it from 2001-2:
http://groups.google.co.uk/groups?q=ntl%20dead%20ip&hl=en&lr=&sa=N&tab=wg

I don't think there was ever a proper solution; NTL might have made some
changes to the DNS servers and/or proxies. Sometimes manually defining a
proxy helped - see the advice at

http://homepage.ntlworld.com/robin.d.h.walker/cmtips/trancache.html

and look at

http://www.go.to/ntlworld.faq

Rob

[Me]

Post by Rob Chambers

Post by Me
I'm told the NTL proxy server you connect through depends on where you
live so this may be relevant. We are all dialling in from Scotland.

NTL

Post by Rob Chambers

Post by Me
said delete cookies, clear cache etc which isn't the problem.
Anyone else having similar problems?

I have occasionally in the past; it used to be quite common and was
known as the "dead IP problem".
Sticking "ntl dead ip" (without quotes) into Google Groups turns up a

http://groups.google.co.uk/groups?q=ntl%20dead%20ip&hl=en&lr=&sa=N&tab=wg

Post by Rob Chambers
I don't think there was ever a proper solution; NTL might have made some
changes to the DNS servers and/or proxies. Sometimes manually defining a
proxy helped - see the advice at
http://homepage.ntlworld.com/robin.d.h.walker/cmtips/trancache.html

Thanks for that. I had tried adding a few proxies manually but I never
found it that successful and it feels a bit like a cover up fix rather
than NTL actually fixing the problem. Support have asked for a load more
information which I have provided so hopefully if I stick at it they will
be able to pinpoint the problem with the servers.

The problem does seem restricted to the 217.137.240 range of IP
addresses. All others have worked fine. It's just hard to get a
connection to the others! When testing the connection at
http://www.lagado.com/proxy-test the ones that work say:

Proxy Test
This request appears to have come via a proxy.

The ones that don't work and sadly are more frequent say:

Proxy Test
This request appears NOT to have come via a proxy.
The request appears to have originated from host
host217-137-240-xxx.no-dns-yet.ntli.net which has ip address
217.137.240.xx

I'm guessing the "no-dns-yet" is relevant seeing as the errors are DNS
related.

Any server type people able to comment?

[News Reader]

Hi,
...

Post by Me
I'm guessing the "no-dns-yet" is relevant seeing as the errors are DNS
related.
Any server type people able to comment?

I believe this just means that NTL have not assigned a final / permanent DNS
name for this IP address (range) (e.g. containing their standard format -
e.g. m000-mp0-cvx0a.hud.ntl.com).

As for your main problem / issue the old (ntlworld / 62.253. IP addresses)
used / use a transparent [Inktomi] cache proxy server. These have / had a
number of bad habits.

The new NTL Freedom (217.137. IP addresses) don't seem to have a transparent
cache proxy server. This means that every page request is dependent on NTLs
DNS servers successfully returning the correct IP address for the site in
question. Sadly, NTLs DNS servers seem to be somewhat notorious! E.g. / i.e.
regularly failing to respond to a proportion of requests (resulting in a
page being incorrectly reported as not found / 404 errors). This may extend
occasionally to NTLs DNS system being out of date (in terms of reflecting
changes to domain records) or incorrect entries existing in their system
(i.e. NTLs DNS servers may have failed to update to the latest record for a
site or may have incorrect information for a domain).

Interestingly, this is one thing that NTLs transparent cache proxy servers
can sometimes help with. I.e. they may have cached the page so it is
available where without their use the DNS issues may prevent access.

Solutions include to re-attempt the request several times (i.e. refresh the
page, CTRL F5 [force complete refresh], close browser and re-open). You
should not need to actually disconnect and reconnect (least of all to get
one of a particular range of IP addresses).

Alternatively, find out the actual IP address of the site(s) in question and
just use that when a given ntl connection seems to be failing to provide
correctly resolved DNS lookups. E.g. / i.e. the IP address of
www.ntlworld.com is 62.253.162.30 .

Hope this helps.

Best wishes,



News Reader

P.s. In any event hopefully ntl will fix the fundamental underlying problem
/ will be able to help you given the extra information you have provided
them with.

[Me]

Post by News Reader
Hi,

Post by Me
I'm guessing the "no-dns-yet" is relevant seeing as the errors are DNS
related.
Any server type people able to comment?

I believe this just means that NTL have not assigned a final /

permanent DNS

Post by News Reader
name for this IP address (range) (e.g. containing their standard format -
e.g. m000-mp0-cvx0a.hud.ntl.com).
As for your main problem / issue the old (ntlworld / 62.253. IP addresses)
used / use a transparent [Inktomi] cache proxy server. These have / had a
number of bad habits.
The new NTL Freedom (217.137. IP addresses) don't seem to have a transparent
cache proxy server. This means that every page request is dependent on NTLs
DNS servers successfully returning the correct IP address for the site in
question. Sadly, NTLs DNS servers seem to be somewhat notorious! E.g. / i.e.
regularly failing to respond to a proportion of requests (resulting in a
page being incorrectly reported as not found / 404 errors). This may extend
occasionally to NTLs DNS system being out of date (in terms of

reflecting

Post by News Reader
changes to domain records) or incorrect entries existing in their system
(i.e. NTLs DNS servers may have failed to update to the latest record for a
site or may have incorrect information for a domain).
Interestingly, this is one thing that NTLs transparent cache proxy servers
can sometimes help with. I.e. they may have cached the page so it is
available where without their use the DNS issues may prevent access.

Yeah ironically it's the ones with a cache that are working.

Post by News Reader
Solutions include to re-attempt the request several times (i.e. refresh the
page, CTRL F5 [force complete refresh], close browser and re-open). You
should not need to actually disconnect and reconnect (least of all to get
one of a particular range of IP addresses).

I have tried refreshing with and without CTRL F5 in the past, (just tried
again too) but it doesn't seem to make any difference. Also the problem
affects email and ftp, ie when I get one of the dodgy IP addresses then
email and ftp do not work on the domain. All that has worked is multiple
reconnecting until an IP address in the 62.252.152 range is found. Got
one from a different range tonight that also worked, 213.104.120.13 which
again is a proxy.

Post by News Reader
Alternatively, find out the actual IP address of the site(s) in question and
just use that when a given ntl connection seems to be failing to provide
correctly resolved DNS lookups. E.g. / i.e. the IP address of
www.ntlworld.com is 62.253.162.30 .
Hope this helps.

Yes thanks for the info.

Post by News Reader
P.s. In any event hopefully ntl will fix the fundamental underlying problem
/ will be able to help you given the extra information you have provided
them with.

I hope they can fix it. It affects myself and two other family members
with separate NTL accounts so I guess it must affect others, some of whom
may just think the particular site that has the error is "down" and not
realise it is an NTL issue.

[News Reader]

Post by Me
I hope they can fix it. It affects myself and two other family members
with separate NTL accounts so I guess it must affect others, some of whom
may just think the particular site that has the error is "down" and not
realise it is an NTL issue.

Hi,

If you can give example details of one of the sites that is not working I am
sure I and others can try and do some checking for you.

There should be no need to disconnect and reconnect in order to reach a
site.

Best wishes,



News Reader

[Me]

Post by News Reader

Post by Me
I hope they can fix it. It affects myself and two other family members
with separate NTL accounts so I guess it must affect others, some of whom
may just think the particular site that has the error is "down" and not
realise it is an NTL issue.

Hi,
If you can give example details of one of the sites that is not working I am
sure I and others can try and do some checking for you.
There should be no need to disconnect and reconnect in order to reach a
site.

If there are DNS problems on certain dialup connections then I think a
reconnect is the only option, other then setting DNS manually or a proxy
but I'd rather they just fixed the problem.

One site example is www.brewshop.co.uk

[News Reader]

Hi,

"Me" <news-***@REMOVETHISTOEMAILntlworld.com> wrote in message news:VivTd.417$***@newsfe5-gui.ntli.net...


...

Post by Me
If there are DNS problems on certain dialup connections then I think a
reconnect is the only option, other then setting DNS manually or a proxy
but I'd rather they just fixed the problem.

I have done some further investigating based on the example site you gave
and it appears the problem is not DNS related but routing. The routing to
the example site through the "new" or "newer" ntl freedom access platform
seems to be broken.

I.e. DNS lookup on the example site works fine on both the new and old
platforms. However, only the old platform is actually able to find a route
to the site.

Hopefully ntl will correct the problem. An interim solution is to manually
dial in to the "old" / ntlworld platform. I am not sure how much you know
about seting up dial-up connections but the essence is that just the dial-up
number needs to be changed (or create a new connection using the alternative
dial-up number).

In summary:

new / ntlfreedom dial-up access number(s): 0808 990 9877 format
old / ntlworld dial-up access number(s): 0800 5190 600 format

You may find that you need to use the 141 withold number prefix and / or the
1263 ntl network prefix. The 141 prefix may be needed because ntl may block
your call if they can identify the number you are calling from and believe
you are supposed to be using the new ntlfreedom access platform. The 1263
prefix may be needed because this used to be part of the access number for
the old platform and connection to the old access number may be refused if
dialed from outside of the ntl network. Thus in summary, the number you
should try for the "old" platform connection is:

141 1263 0800 5190 600

Hope that helps.

Certainly seems to work for me. This should essentially ensure that you
always get one of the old platform IP addresses and a cached connection.

Let me know how you get on or if I can help any more.

Best wishes,



News Reader

[Me]

Post by News Reader
Hi,
...

Post by Me
If there are DNS problems on certain dialup connections then I think a
reconnect is the only option, other then setting DNS manually or a proxy
but I'd rather they just fixed the problem.

I have done some further investigating based on the example site you gave
and it appears the problem is not DNS related but routing. The routing to
the example site through the "new" or "newer" ntl freedom access platform
seems to be broken.
I.e. DNS lookup on the example site works fine on both the new and old
platforms. However, only the old platform is actually able to find a route
to the site.
Hopefully ntl will correct the problem. An interim solution is to manually
dial in to the "old" / ntlworld platform. I am not sure how much you know
about seting up dial-up connections but the essence is that just the dial-up
number needs to be changed (or create a new connection using the alternative
dial-up number).
new / ntlfreedom dial-up access number(s): 0808 990 9877 format
old / ntlworld dial-up access number(s): 0800 5190 600 format
You may find that you need to use the 141 withold number prefix and / or the
1263 ntl network prefix. The 141 prefix may be needed because ntl may block
your call if they can identify the number you are calling from and believe
you are supposed to be using the new ntlfreedom access platform. The 1263
prefix may be needed because this used to be part of the access number for
the old platform and connection to the old access number may be refused if
dialed from outside of the ntl network. Thus in summary, the number you
141 1263 0800 5190 600
Hope that helps.
Certainly seems to work for me. This should essentially ensure that you
always get one of the old platform IP addresses and a cached

connection.

Post by News Reader
Let me know how you get on or if I can help any more.

Thanks for the suggestions. The old number stopped working for me some
time ago but I gave it a go. The number on its own gave an unobtainable
tone or the BT woman saying the number had not been recognised. With 141
and/or 1263 I got a constant engaged tone.

I think I've given them enough time to come up with a fix and coupled
with the recent email problems etc I think I am just going to go
elsewhere.

Thanks for the help.

[News Reader]

"Me" <news-***@REMOVETHISTOEMAILntlworld.com> wrote in message news:Bm8Ud.989$***@newsfe3-gui.ntli.net...


...

Post by Me

Post by News Reader
Let me know how you get on or if I can help any more.

Thanks for the suggestions. The old number stopped working for me some
time ago but I gave it a go. The number on its own gave an unobtainable
tone or the BT woman saying the number had not been recognised. With 141
and/or 1263 I got a constant engaged tone.

There are other alternatives such as trying 0800 519 0100 (the very old /
original ntl world access number - although usually this just reroutes to a
page about downloading the ntl freedom dialler software - although I believe
this number may work for those whose access to the number ending 0600 has
been discontinued). Otherwise, there is a whole list / range of alternative
access numbers you can try which are variously for regional access points on
the ntl world / freedom platform and / or tesco and virgin ISP services
which I understand share the same ntl network (and possibly user
database[s]).

Post by Me
I think I've given them enough time to come up with a fix and coupled
with the recent email problems etc I think I am just going to go
elsewhere.

Sadly, I can well understand that you should not feel you have to nor have
to spend significant amounts of time finding workarounds for a problem
inherent with ntls service :( .

Post by Me
Thanks for the help.

You are welcome.

The other alternative is to specify a proxy server on the normal ntl access
number you use which should well solve the problem. If you are interested in
this and would like some further information on this let me know and I will
see if I can help.

Best wishes,




News Reader

P.s. I have just noticed that one of the sites I wanted to reach is
suffering the same problems and have just created a newsgroup post about
this. Fortunately I am still able to use the 0600 suffix access number. None
the less, this does show the problem may be more significant / widespread
than I or possibly ntl had realised.