Can't get in to Metafilter with Firefox

April 2, 2008 9:53 AM

I can't log in with Firefox, Safari's working just fine. Following Jessamyn's suggestions I deleted cookies & disabled greasemonkey, but just get directed back to MeFi homepage as not logged in. Anyone else having trouble? Anyone solved it?

I'm feeling a bit thick-headed, so it could be something simple. Promise never to log out again.

posted by tula to Bugs at 9:53 AM (19 comments total)

How can you be logged in to MetaTalk but not to MetaFilter?
posted by yhbc at 10:06 AM on April 2, 2008

This will happen if you have cookies completely disabled. You might go in and check your Firefox preferences to be sure. Under the Privacy tab, make sure "Accept cookies from sites" is checked.

Beyond that, you might look through your Add-Ons and see if there are any related to privacy or security that might be managing cookies for you. Try disabling, logging in, and see if that was the culprit.
posted by pb (staff) at 10:06 AM on April 2, 2008

Tools--Options--Privacy--Cookies--Exceptions--click Status:
That will order your cookies into Allow, Allow for Session, Block.
You might have a MetaFilter cookie Blocked.
posted by weapons-grade pandemonium at 10:13 AM on April 2, 2008

yhbc: "How can you be logged in to MetaTalk but not to MetaFilter?"

They probably used Safari to make this post.
posted by booticon at 10:18 AM on April 2, 2008

yhbc, like I said, Safari's working fine. pb, tried with cookies cleared, enabled, disabled, every combo I can imagine. I've disabled some add-ons...but that privacy/security realm seems like a possibility....will noodle about...
posted by tula at 10:19 AM on April 2, 2008

tula, have you tried running Firefox in Safe Mode? I'm guessing you're using OSX (unless you're nutso enough to use Safari in Windows), so if you haven't tried it already, fire up a terminal window and type in /Applications/Firefox.app/Contents/MacOS/firefox -safe-mode. This disables all extensions and themes.
posted by booticon at 10:23 AM on April 2, 2008

This happened to me yesterday. For some reason when I deleted the STOPIT cookie, Firefox automatically added metafilter.com to the exceptions list. Like w-gp said, make sure you check Tools->Options->Privacy->Exceptions.
posted by team lowkey at 10:28 AM on April 2, 2008

I just got in using a different computer, so it's something specific to mine that's the problem.

booticon, will try that next. And thanks everyone, by the way. tl, yes, this started yesterday with the stopit thing, so maybe...
posted by tula at 10:31 AM on April 2, 2008

By default, if you delete cookies from a site, Firefox will refuse all further cookies from that site, forever.

Go to Tools/Options, click the Privacy tab, and make sure 'accept cookies from sites' is checked. Then click the Exceptions button, and scroll through the list. Find metafilter.com (also check for ask.metafilter.com, metatalk.metafilter.com, and www.metafilter.com) and remove them from exceptions.

If you then refresh the main Metafilter page and log in, it will probably work.
posted by Malor at 10:37 AM on April 2, 2008

IN! You are geniuses.
posted by tula at 10:38 AM on April 2, 2008

You are geniuses.

A little known fact that MeFi membership requires a minimum 145 IQ. Of course, that's when you sign up. Your IQ does drop a point or two every time you read a politics thread.
posted by wendell at 10:56 AM on April 2, 2008

Hey, no politics thread bashing allowed in my yard.
posted by tula at 11:15 AM on April 2, 2008

Yay, this is all good stuff to keep in mind the next time we go fooling around wiht cookies. Thanks everyone.
posted by jessamyn (staff) at 7:13 PM on April 2, 2008

For future reference, if you are in a similar situation and cookies don't make any difference, it could be your MTUs. This used to drive me nuts when I was at my dad's, and it just happened again on my own computer when I installed a new hard drive last week. For some reason, all the MeFi sites wouldn't load for me (OS X: Firefox, Camino, Opera, or Safari), and they were the only ones affected.

To solve it, I had to go to System Preferences/ Network/ Show: Built-in Ethernet and go to the Ethernet tab on the right. Then change Configure: from Automatically to Manually (Advanced). This opens up more options, the last one of which (Maximum Packet Size (MTU) is set at Standard (1500). If I uncheck this and check Custom, then pick a ridiculously low number (say 200), and Apply Now, the MetaFilter sites work again. After which, I can reset the number in the Custom box back up much higher, even to 1500 where it was originally, and they still work. (Currently, for no particular reason, I have it set at 1480.)

I have little idea what MTUs are/do, particularly, but for some reason OS X browsers occasionally get cranky when they are set at Standard. (And, without the MeFi sites, what good is the Internet?)

Also discussed here, here, and here.
posted by LeLiLo at 9:06 PM on April 2, 2008 [1 favorite]

Huh. Also discussed here. I had no idea MTUs are such a problem. I also still have no idea what they do, either, but there you go.

It's funny to me that I solved my problem by typing in an apparently random number into something that I don't understand. They were right; any sufficiently advanced technology is indistinguishable from magic.
posted by yhbc at 9:11 PM on April 2, 2008

yhbc, it would have been magic if you had typed some random number into something you don't understand and it had fixed my problem.
posted by fantabulous timewaster at 9:27 PM on April 2, 2008

MTUs are the maximum packet size that can be sent. Ethernet is typically 1500 bytes, but many providers, especially DSL providers running PPPoE, make this slightly smaller.

What's supposed to happen is that your computer starts sending traffic with 1500-byte packets, and then one or more of the routers along the way are supposed to tell you, "hey, I'm having to fragment, you need to reduce your frame size." This message is sent with ICMP, a separate protocol. Many routers and firewalls just drop all ICMP, period, meaning that your computer never gets that message, and doesn't reduce the MTU for that connection.

Even so, most of the time, things will still work; the packets will get fragmented into multiple pieces, and then reassembled on the other end, and you won't see any visible difference. The routers in between are having to forward twice as many packets as they should, but you shouldn't be aware of that. If any router along the way, though, is configured to drop fragmented packets, which is uncommon but possible, AND your firewall refuses all ICMP, then as soon as big packets start to flow, the connection will fail. That would probably manifest as beginning to connect to MeFi, and then the connection stalling partway through, perhaps with words on the screen, perhaps not.

If you think you have an MTU problem, this is the way to test (under the command prompt in Windows):

ping -f -l 1472 www.metafilter.com

This says, set the don't fragment bits on packets, and send packets of size 1472 to www.metafilter.com. If you get back replies, then your connection is 1500-byte clean and MTU is likely not your problem. Stop there. Look for other problems instead. :)

If you don't get replies, try dropping that number by about 10 at a time until you find a number that works... and then increase it until you determine the exact size that works, the biggest packet you can send. Add 28 to that value (the overhead of a ping packet), and that's your MTU to Metafilter.

That's probably also your MTU to EVERYWHERE, so run the same test to a few other places to make sure it seems to be working (try a straight ping first to make sure the site responds to pings!) ... and if you get the same result across a few sites, you've nailed down your MTU.

Here are instructions for most OSes on adjusting MTU size. On XP, that's a registry setting. They don't cover Linux, but if you're a Linux geek, you can probably figure it out yourself. :)

Note also: you can probably also fix MTU problems by replacing your firewall/router with a smarter one that allows through ICMP messages that are related to your connection attempts. If that's not an option, this is a way to work around the problem.
posted by Malor at 11:51 AM on April 3, 2008 [1 favorite]

By the way, I get ping replies with the 1472 size, so MeFi itself is 1500-byte clean. If you're having a problem, it's probably your provider, combined with your router and firewall.
posted by Malor at 11:53 AM on April 3, 2008

Also: some providers (mine is like this) give you the choice of PPPoE or PPPoA. If you're having MTU trouble, and you're using PPPoE, and you don't feel like fooling about with your registry, you might want to tell your DSL router to use PPPoA instead. There's one less layer of headers with PPPoA, and sometimes that can make the difference you need.
posted by flabdablet at 4:58 PM on April 3, 2008