Vanishing Apod

[r.w.b]

We're looking forward to seeing it. APOD has gone AWOL here since yesterday evening.

[owlice]

Where's "here"?

[neptunium]

And what's AWOL? A is obviously for astronomy and O for of, but what about W and L.

[Beyond]

And what's AWOL? A is obviously for astronomy and O for of, but what about W and L.

It's a military abbreviation for Absent With Out Leave. For non-military people It's Uh-Oh, you took off when you weren't supposed to, and didn't tell anyone. You're in BIG trouble now!!

[Euan]

Has anything been changed recently that might affect access? I have been unable to see apod for the last four days and am suffering from withdrawal symptoms. It is as if the site no longer exists.

Euan

[owlice]

Which site are you trying to look at (what's the URL)? What are you getting when you try to access it (what's the error message)? Are you trying to access APOD through a particular software (such as the automatic downloader program that doesn't work under Windows 7)? What browser are you using, and what have you done to try to rectify the problem (as in, have you tried another browser)?

Answers to these questions may help pinpoint what the difficulty is, as the problem appears to be at your end, since APOD is accessible to others.

[RayM]

I've been having a similar problem, starting around the same time, and at first I thought it was my ISP (Cablevision, NY). However, trace route shows the last resolved hop to be within NASA, at 198.119.56.66. Occasionally, part of the site will display, but inevitably it eventually times out.

I've tried: multiple browsers, multiple platforms, multiple machines, and two separate locations served by my ISP. I've powered things off and on (cable modems, routers, computers), all to no avail. And yet, from my work location, everything is perfectly fine.

Has something changed recently in the NASA network? It sure feels like it...

[tarazed]

Not sure if this is the appropriate forum to bring this up. Since New Year I have been unable to access the APOD site. Other people on the web seem to have had trouble also. http://www.isup.me indicates that the NASA site is working fine so the problem lies between NASA and me. Most of the suggestions posted elsewhere point to a problem DNS server somewhere so flushing the DNS cache should force rerouting but that does not work for me. I am using Mozilla Firefox in Mageia 1 Linux and have no problems with any other site. At first I assumed that the site was under maintenance over the holiday period but this is now January 12. Has anybody here had any such problems? I have followed APOD since it started. It is always the first link I click on at the start of the day and it has never failed before apart from the odd hiatus.

[Case]

Does http://129.164.179.22/ work for you?
If so, then it is indeed a DNS problem.

[RayM]

Been there, done that... no good.

[tarazed]

No, using the bare URL shows the same symptom, no immediate access.

Traceroute gets as far as nasa.gov:

excerpt -

Code: Select all

13  ae-11-60.car1.Washington1.Level3.net (4.69.149.3)  105.403 ms ae-31-80.car1.Washington1.Level3.net (4.69.149.131)  104.832 ms ae-11-60.car1.Washington1.Level3.net (4.69.149.3)  105.078 ms
14  * * *
15  * * *
16  * * *
17  * * cn-fw-x.gsfc.nasa.gov (198.119.58.6)  110.786 ms
18  * * *

[tarazed]

I have been thinking more about this. Here we have a number of people
with different hardware, different browsers, ISPs and operating
systems, who suddenly experienced the same problem in accessing APOD,
all about the same time, which would indicate that something outside
their control has changed. We cannot get past some server on the NASA
network yet the vast majority of people have had no trouble at all.
Something somewhere closer to NASA than to us has changed for the
worse for a handful of users. It might be something which requires us
to make some change at our end, but who knows? Is it a routing
problem?

antwrp.gsfc.nasa.gov and apod.nasa.gov both resolve to 129.164.179.22.
traceroute gets as far as cn-fw-x.gsfc.nasa.gov => 198.119.58.6.
dig reports NXDOMAIN (non-existent domain) on both addresses, possibly
because the domains are private? ping fails but it succeeds for the
server one hop back, 4.69.149.3. Tried traceroute again and ended up
on a different server:

Code: Select all

16  * * cne-gw-sip.gsfc.nasa.gov (198.119.56.66)  94.879 ms

so it looks like they have a server farm there and all of them hanging on my requests.

[tarazed]

I do not think anything I have said has much relevance to this problem. Every now and again the site decides to try to load but is excessively slow. The text comes up fairly quickly but images load at 100 bytes/sec (on a 50 MHz connection) and the server times out eventually.

[RayM]

I've seen the same IP addresses from traceroute that you reported.. it can't be coincidence.

On the other hand, if I traceroute from work, I see *the same* IP addresses, but I have no problems accessing APOD.

[Chris Peterson]

I've seen the same IP addresses from traceroute that you reported.. it can't be coincidence.

On the other hand, if I traceroute from work, I see *the same* IP addresses, but I have no problems accessing APOD.

Yes, I think the traceroute information isn't providing much information about what is wrong. I have no problem accessing APOD, but the traceroute fails pretty quickly once I'm inside the NASA system. They presumably have some internal servers that don't respond to echo requests, and are thus largely invisible to traceroute.

Code: Select all

 16   166 ms   200 ms   167 ms  cne-gw-sip.gsfc.nasa.gov [198.119.56.66]
 17   180 ms   151 ms   174 ms  cn-fw-x.gsfc.nasa.gov [198.119.58.6]
 18   176 ms   179 ms   173 ms  rtr-core-gw.gsfc.nasa.gov [128.183.238.3]
 19     *        *        *     Request timed out.
 20     *        *        *     Request timed out.
 21     *        *        *     Request timed out.
 22     *        *        *     Request timed out.
 23     *        *        *     Request timed out.
 24     *        *        *     Request timed out.
 25     *        *        *     Request timed out.
 26     *        *        *     Request timed out.
 27     *        *        *     Request timed out.
 28     *        *        *     Request timed out.
 29     *        *        *     Request timed out.
 30     *        *        *     Request timed out.

Trace complete.

They might have a server running some sort of blacklist. Any chance you folks having problems share a common ISP?

[owlice]

I've let the NASA folks know about this problem. Thanks very much for your various work in trying different things to rectify the issue.

[TNT]

Chris, what do echo requests have to do with it? I think I might know of a way to resolve the problem, although I'm far from confident.

And tarazed, are any of those numbers IP addresses for your router?

[geckzilla]

I've seen issues like this in similar circumstances. What it usually turns out to be is one server on the fritz that happens to be one of the hops that a particular group of people need in order to connect to their goal. The only way to get it fixed is to find that hop and contact the admins... but alas, I do not know how to determine who the broken hop is.

[bystander]

Until the problem is resolved, try one of the mirror sites listed in About APOD. This link is from the UK mirror maintained at the University College London.

[tarazed]

No, none of the addresses correspond with anything on my LAN.

[tarazed]

Thanks for the UK mirror link. That responded instantly.

[r.w.b]

Where's "here"?

Apologies for the omission; I'm in Lincolnshire, England. ISP is Virgin Media - who might be the cause of the problem.

APOD is still failing to load, despite my having tried using different computers, browsers and five different operating systems. I've reset browsers, cable modem, routers, and so on, as well as temporarily turning off firewalls, but without having APOD load reliably. All other web pages accessed look O.K.

It first had problems on the 6th of January, the day before I reported the issue and for a few days. APOD loaded properly yesterday, but not today.

[RayM]

They might have a server running some sort of blacklist. Any chance you folks having problems share a common ISP?

I'm pretty sure this isn't the problem, since the server sometimes responds with at least a partial page. If it's of any relevance, though, my ISP is Cablevision, NY (aka OptimumOnline)

[RayM]

Ditto with thanks for the UK link - it also worked for me. I feel complete once more

[bystander]

APOD is still failing to load, despite my having tried using different computers, browsers and five different operating systems. I've reset browsers, cable modem, routers, and so on, as well as temporarily turning off firewalls, but without having APOD load reliably. All other web pages accessed look O.K.

See Vanishing Apod