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I am having a hard time understanding how the ident protocol works. I came across a summary of how it works at Wikipedia however don't quite follow what it means
The Ident Protocol is designed to work as a server daemon, on a user's computer, where it receives requests to a specified port, generally 113. In a query, a client specifies a pair of ports (a local and a remote port). The server will then send a specially designed response that identifies the username of the user who runs the program that uses the specified pair of ports.
For example I assume that every OS has an ident server running. If so where does it receive an ident request to a specified port? In that query it states the client specifies a part of ports? Which is the client and which is the server?
Thanks. So does it mean if I want to connect to an IRC service, I need to have an ident server running on my PC? If so when I connect to an IRC server/service I take it it would attempt to connect to the ident server on my PC? – PeanutsMonkey – 2011-08-20T07:36:10.157
Yes, that's right. (Except Ident is very rarely required, most networks consider it optional.) – user1686 – 2011-08-20T08:05:29.103
… but they'll nonetheless hang for a minute or so at connection time whilst they time out trying to talk to a nonexistent
ident
server. ☺ – JdeBP – 2011-08-20T23:39:07.203@JdeBP: Not if your computer correctly rejects the TCP connection attempts. (Often firewalls drop them quietly instead of TCP RST.) – user1686 – 2011-08-21T06:04:15.203
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Amazingly, we live in a world where people like Steve Gibson give top marks for computers that do not exhibit any such correct behaviour. ☺
– JdeBP – 2011-08-22T01:22:53.860(In other "news", your network is secure if it's behind a NAT, and breaking PMTUD by blocking all ICMP packets is the new hot thing in computer security.) – user1686 – 2011-08-22T01:34:34.943
@grawity - What is PMTUD? In the case of ident being rarely required, what purpose does it serve? – PeanutsMonkey – 2011-08-22T01:56:55.813
@Peanuts: The comment was not related to Identd. (PMTUD is Path MTU Discovery.) – user1686 – 2011-08-22T09:30:03.617
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I've lived in a Gibsonian world at at least one job. IRC users whose network administrators are likewise Gibsonians simply have to learn to love the long wait for the
– JdeBP – 2011-08-23T23:32:06.117NOTICE AUTH :*** No Ident response
message. Interestingly, the conclusion that Steve Gibson's notions of stealth ports are "a little bit nutty" and "fearmongering" currently wins the popular vote. That doesn't help those sentenced to live with Gibsonians, though. ☺