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| Thread ID: 22538 | 2002-07-23 22:57:00 | Hot rodding PCs cause online banking problems | tweak'e (174) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 64693 | 2002-07-23 22:57:00 | >"We send a response back saying 'don't fragment this packet' and we're going to send it at 1500 bytes," which is the standard size. The packet then travels back to the user via a generic routing encapsulation (GRE) protocol tunnel, which will only accept packets that are smaller than 1476 bytes. i don't get this. why send a 1500 byte packet if they know that the tunnel will only handle 1476? why don't they just send it at 1476? |
tweak'e (174) | ||
| 64694 | 2002-07-23 23:49:00 | >i don't get this. why send a 1500 byte packet if they know that the tunnel will only handle 1476? why don't they just send it at 1476? The question is, do they know it only handles 1476? Sounds absurd. And why not fragment the packet? Security reasons? |
Elwin Way (229) | ||
| 64695 | 2002-07-24 04:36:00 | tweak'e: ? Is that quoted bit something you got in a message from a bank's network people? ?:| If it means what I think it means, they have set things up to ignore the results of a protocol negotiation for packet size, and are carrying on on their terms. I suppose their argument might be: "bigger packets have least overhead, therefore we get maximum efficiency by using the maximum size (1500). Pity that the communication efficiency drops to zero when our packets strike a router or other network device which can't handle that size without fragmenting." Or, "We're the XXX Bank; the rest of the world is only customers , so they can adapt to us". :D |
Graham L (2) | ||
| 64696 | 2002-07-24 07:46:00 | Coz the GRE header is 24 bits and the default MTU is 1500. Sucks aye? :| | BIFF (1) | ||
| 64697 | 2002-07-24 07:47:00 | I'm not exactly sure what you guys are talking about, but I thought I could add an interesting note to this post... I like to use opera as an alternative to IE5. I like opera. My online banking won't let me USE Opera. Transactions and the like are refused when using opera, so everytime i got to do some banking ( paying rent etc) over the internet, I have to load up IE. I tried emailing the bank and asking them to consider allowing Opera and other browsers, but here I am 2 weeks later still waiting for a response... this is westpac trust i'm talking about. Maybe they think that my $150 per week (student load) isn't enough to warrant a reply... It's not enough that I pay fees and the like (which pay their bloody wages), they also are trying to decide what browser I'm going to use, and they are going to be downright rude about it. I mean really, what business doesn't reply to their customers!? Like graham said... "We're the XXX Bank; the rest of the world is only customers , so they can adapt to us". |
loser (538) | ||
| 64698 | 2002-07-24 10:51:00 | hi graham. the quote is from pcworld article in the news. mayby i'm missing the point but something didn't sound right. |
tweak'e (174) | ||
| 64699 | 2002-07-24 22:53:00 | loser, i guess your a loser, cause if you had any idea you would know that banks don't charge fees to students. | roofus (483) | ||
| 64700 | 2002-07-25 00:43:00 | no need for name calling buddy. Actually, SOME banks don't charge fees to students. Mine does. So why don't I change to a different bank? Well, I don't know. I haven't got around to it yet, and plus, I have so much stuff already set up for my online banking etc. A few other reasons. That's not the issue though. The issue is that I don't like not being able to use my browser of choice! ;) |
loser (538) | ||
| 64701 | 2002-07-25 06:48:00 | I saw our sponsor's product after I posted that . I agree tweak'e, seems the wrong way around . Perhaps the spokesdrone was from public relations or marketing, and just ignorant . If the bank knows that even a few routes can't handle over 1474, they wouldn't send 1500 . That would stop it working . They want it working . So a "clever" customer bumps up the MTU . But what sort of TCP stack would not step down if it doesn't get any ACKs? (All right, an MS one would :D) . Yes, fragmenting of encrypted packets is a Very Bad Idea . But if one end of a "secure" connection is a bloated, totally insecure piece of software like a browser, MS IE would be about the worst . Even if the new headers allow 24 bits, there are still a lot of routers in the Internet which have limits on packet size based on the old standard . That standard was chosen on the basis of experience . It's a compromise . Longer packets have less overhead, but more chance of getting errors . If there's an error, the packet has to be repeated, and the longer it is, the greater the overhead caused by errors . Admittedly, the lines are better than they used to be, but the packets have to get from one end to the other, and errors can occur at any point . But the way the banks are going, I think I will just use a sock under the mattress to keep my millions . |
Graham L (2) | ||
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