Tag Info

Hot answers tagged

30

You can edit tomcat/conf/server.xml's HTTP/1.1 Connector entry, and add a maxHttpHeaderSize="65536" to increase from the default maximum of 8K or so, to 64K. I imagine that you could up this number as high as necessary, but 64K suffices for my needs at the moment so I haven't tried it. <Connector port="8080" maxHttpHeaderSize="65536" protocol="HTTP/1.1" ...


13

This is a common error. You cannot use a CNAME RR for your root domain (e.g. company.com) and define additional resource records for the same zone. See Why can't I create a CNAME record for the root record? and RFC1034 section 3.6.2 for details: If a CNAME RR is present at a node, no other data should be present; this ensures that the data for a ...


12

You are probably looking for RFC 6056 - Recommendations for Transport-Protocol Port Randomization ("Best Current Practice"). Technically there is no requirement that the ephemeral port be >1024 or random (you could build a system that always initiates connections from port 12 because you like the number 12), it's just not "normal" to do so (and an awful ...


10

@yoonix has sent a link that might have a solution. Link-local, also known as APIPA. 169.254.0.0/16 - This is the "link local" block. As described in RFC3927, it is allocated for communication between hosts on a single link. Hosts obtain these addresses by auto-configuration, such as when a DHCP server cannot be found. If I were your customer, I'd ...


8

Don't do accept-and-bounce, do as much filtering/rejecting at connection time as possible. This helps to prevent Backscatter Emails and Joe Jobs, and keeps unwanted email out of your mail system.


8

You'd think they are valid because the root name-servers are all single-letter hosts (a.root-servers.net), and the DNS spec doesn't create a specific exception for them. The RFC in question is specifically for host-file format, not DNS. DNS was defined in a later RFC (RFC 1035 starts it). RFC 1123 (1989) states it clearly. The syntax of a legal Internet ...


8

It's definitely compliant. The whole point of Quoted-Printable, and the rest of the MIME series of RFCs (RFC 2045 through RFC 2049), is to allow the encoding of data that otherwise would not be valid in e-mail. RFC 2822 explicitly (and repeatedly!) points readers at those RFCs for information on how to do this.


6

I'd go as far as saying that there is no connection, at all, between the records in DNS and what a server tells you its name is, so from a DNS point of view, the only difference between your two scenarios is what name goes where. From the machine's point of view, it doesn't care. However, from your users' perspective, I'd pick one of the two and then stick ...


5

The length of an HTTP GET request is not enforced by RFC2616, as Microsoft reports for its IE max length support page. So, the maximum GET length is a client (browser) related issue. If your app is used by people you can force to use a given browser then you can simply find what is the length this browser support. In every case I suggest a look to the ...


5

Normally, a router would never receive a packet with a hop limit of zero, but it may happen at some point due to sloppy coding or malicious computers or network degradation. The issue is what happens when you decrement something that is zero. If it's unsigned, then it wraps around and lasts another 65535 hops.


5

The preferred option is to bounce immediately at the Internet gateway. This results in a failure for the server (most likely a spambot) that you are rejecting. However, it is simpler to use this to check for the existence of an email address. Accept and bounce is simpler for the Internet gateway, but generates back scatter spam. In effect, you make your ...


5

From Wikipedia: Assigned as "TEST-NET-3" in RFC 5737 for use solely in documentation and example source code and should not be used publicly. - This tells me that you should not use TEST-NET-3. One thing you appear to be overlooking: How do you suppose that you'll be able to communicate with the device or that the device will be able to communicate with ...


5

E-mail without MIME support (which is optional) is defined by RFC 5322, and only allows "printable" ASCII characters. MIME extends this standard and allows other encoding schemes for certain fields (subject included). When encoding a header, you use the "Encoded-Word" method: The form is: "=?charset?encoding?encoded text?=". charset may be any ...


5

RFC 822 actually gives an example of this usage. It required (Section 4.4) that the Sender: header be present when it was used. A.2.7. Agent for member of a committee George's secretary sends out a message which was authored jointly by all the members of a committee. Note that the name of the committee cannot be ...


5

Make it configurable. Should I buy IPv4 addresses? Yeah. TRY THAT. First, you do not buy them, you "lease" them by membership. Second this requires an AS and 2 uplinks. Third, this requires a reason and "we do not want to suppose a proper network infrasctructure" is a reason resulting in laughter (and a rejection), not you getting IP addresses ...


4

In theory, any private IP range could be in use by any private network, so I doubt you'll find a best practice, or anything that's going to be universally applicable if you're hard-coding the address. The best practice would be to make it configurable and allow the client network to assign the device a private address (via DHCP, for example). If that's not ...


4

The mail from: in the smtp conversation is designed to be the place where bounces will go The From: header in the message body is used to display to the recipient and as the reply address if the Reply-to: header isn't set. Emails which shouldn't generate a bounce should set the empty sender in the envelope, for instance a return receipt will usually have: ...


4

Automated processing is a big reason. You want to be able to send any bounces/autoreplies/errors to be processed separately, otherwise those messages disappear, or get ignored, or some poor sap has to dig through them. Yes, adding an X- header for processing is possible, but a lot of the time bounces/etc. won't include the original email or only a mangled ...


4

I have not seen multiple addresses in the From field used for legitimate purposes. The few cases I have seen were on spam, and had multiple copies of the same address. I don't know of any message composition software which support lists in this context. The cases I consider it to could be appropriate are relatively few, and in my experience are handled ...


4

Yes you are correct. The section you quoted says that it must be a quoted string OR a dot atom. Since its clearly not a quoted string (the lack of enclosing " makes that clear) it must be a dot-atom... That leads us to the definition of dot-atom: Look at this except from RFC 5322 (3.2.3 - page 13) (RFC 2822 contains a similar section) the hint is the 1* ...


4

The Neighbor Discover Protocols, of which Router Advertisements are a part, is currently the only way to auto-configure the router options for a client. It's being debated whether this is an actual shortcoming of the DHCPv6 protocol, or if NDP-RA is sufficient. There's more than a few people who contend DHCPv6 is wholly unnecessary and should be deprecated ...


3

Microsoft has published information regarding their journaling format http://technet.microsoft.com/en-us/library/bb331962.aspx However email journaling does not appear to be a formal standard


3

The correct answer would be "read the RFC", but an easier to remember version would be "that's exactly how mailing lists work". You send an email "to" the mailing list, and then it gets delivered to all subscribers. None of the subscribers are in the To, Cc, or Bcc lines.


3

The Content-ID does not indicate that a image should be displayed inline. This header is needed to reference the embedded data within HTML. As an email is a text-message there is no reason to display an image embedded, as long as the mail is plain-text. Some clients does display the data inline regardless of the format is HTML or plain-text. But this is ...


3

I think you're looking for the Content-Disposition header field, which allows you define the presentation style of a body part (such as an image) to be inline or attachment. Here's an inline example created by Thunderbird: --------------040202010204080305090405 Content-Type: image/png; name="test.png" Content-Transfer-Encoding: base64 Content-ID: ...


3

Generally speaking, the hostname should be an A record, since there are places where it's not permitted to use CNAME when that hostname is referred to in other DNS records (e.g. the MX record case you gave). For what it's worth, I'd wonder what you're trying to achieve by having multiple interfaces? If they're to provide redundancy, then a better method ...


3

There are many reasons why the Header and Envelope From addresses may not match. Most concern automated processes sending mail, where delivery issues need to be reported to an address that is not representative of who sent the mail, or who it was sent on behalf of, or who should be replied to. Mailing lists as you've pointed out are a good example. The ...


2

I use zonecheck (http://www.zonecheck.fr/). It doesn't do everything that some paid DNS checking services do, but it does do many check, is both free and Free, and is available in many distros' standard repositories (see here and here for Debian/Lenny) so is relatively easy to install on your own internal services instead of relying on other sites.


2

As host names were around before anyone even thought about writing an RFC about them I can't see any reason single character host names should suddenly become "illegal". That particular RFC lost me when it stated This RFC is the official specification because an RFC is NOT a standard. Not even close. Despite the foregoing, it must be noted that the ...


2

Have you got to this in 2460: 8.2 Maximum Packet Lifetime Unlike IPv4, IPv6 nodes are not required to enforce maximum packet lifetime. That is the reason the IPv4 "Time to Live" field was renamed "Hop Limit" in IPv6. In practice, very few, if any, IPv4 implementations conform to the requirement that they limit packet lifetime, so this ...



Only top voted, non community-wiki answers of a minimum length are eligible