On Wed, 23 Oct 2002, Gelu Gogancea wrote: > My dear friend, Same to you
> TCP/IP is a protocol with KNOWLEDGE at ICMP level(see RFC792 ). > The DNS server have a different purpose(see RFC 1034 or RFC 952 "HostNames > table"). > Ping work at ICMP level. Well well.. but it can't send ICMP echo packets to a hostname. Even ICMP knows nothing about pure hostnames. > The KERNEL is responsible about what is happened in the OS including the > TCP/IP protocol. > The TCP/IP IPV4/IPV6 and functions like > socket(),accept(),listen(),bind()...etc are implemented on the KERNEL Did I say they werent? > level...also the sockaddr structure type and many others. > Functions like gethostbyname(),gethostbyaddr(),res_init,res_query()...etc > and hostent structure type are implemented in glibc. Correct. > Without all this, the TCP/IP communication CAN NOT EXIST. > MySQL have the own way/functions for resolving hostnames but which is based > on the glibc functions. > The glibc defines the SYSTEM CALLS and others functions and it used by the > C/C++ compiler. > In fact by adding IP address in /etc/hosts, the glibc function > gethostbyaddr() reserve the RIGHT MEMORY SIZE FOR IT(seems to be a recast to > int type). > If the IP address/Alias is not present in "hosts", this function make an > wrong allocation memory and for this MySQL daemon is crashed. > That's it. Seems to be. Got it. :-) > In my previous e-mail i don't say nothing about Domain Class(A,B,C) or > canonical name or reverse lookup or other things which is on DNS > responsibility.I try to say about how it work and was my wish to not to be > too technical. Not in those words, but you talked about host resolving. That is certainly DNS functionality. You talked about SERVER... it can be understood in many different ways. But it seems to me that this issue is resolved and over. Best regards, Iikka > ----- Original Message ----- > From: "Iikka Meriläinen" <[EMAIL PROTECTED]> > To: "Gelu Gogancea" <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Wednesday, October 23, 2002 2:11 PM > Subject: Re: RedHat 8 and mysql-server-3.23.52-3 > > > Hi! > > On Wed, 23 Oct 2002, Gelu Gogancea wrote: > > > Hi Iikka, > > > > My opinion: > > Doesn't matter what type of client it is(whatever OS).TCP/IP it's the same > > for all.One property of the SERVER it to resolving hosts.And this is done > by > > IP-hostname mapping/resolving is usually done by DNS servers, not the MySQL > server, assuming that they're not running on the same box. :-) There are > several ways for resolving addresses. > > > using > > KERNEL functions.By adding in "hosts" file(in the SERVER MACHINE) the IP > > address of the client machine which want to connect to the SERVER, help > > SERVER for resolving the hostname.KERNEL make a lookup to the hostnames > > which is associate with the IP address. > > AFAIK, IP-to-hostname mapping isn't done by _kernel_ functions. At least > the Linux kernel knows very little about hostnames. Some exotic Unixes may > implement this differently, but no operating system I'm aware of has kernel > interfaces for name resolution. > > Making the server recognize the client correctly with an updated /etc/hosts > seems logical enough. It's strange, though, to have to make changes on the > server for clients to be able to connect. > > > For using this functions IS NEED TO HAVE the properly "system call" > library > > which is(in this case) GLIBC.2.2.40.If some incompatibilities(BUGS) exists > > between this, a lot of problems can be raised after compilation.For this > > reason EGOR send a strongly message to all to make a downgrade to a > version > > of glibc which is stable. > > Here you get it right. glibc is much more responsible for > ip-hostname-mapping than the operating system kernel itself. Kernel > implements the IP protocol with dotted-format addresses, and it expects > user-mode libraries to do any necessary conversions. That is, when you do > this: ping www.google.com the ping binary calls a couple of conversion > functions in user-mode libraries so that it can pass a real IP address to > the kernel/protocol interface. --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
