Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique?
Given that the top 3 bytes are manufacturer ID, using all six really wouldn't make much difference unless you have the same bottom 3 bytes from the different manufacturers which is somewhat unlikely. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 5:55 AM To: general-networking Subject: default hostname Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique? _______________________________________________ General http://community.qnx.com/sf/go/post61988
Unlikely but possible. I`d prefer not having to worry if in 10 years from now we need to swap a computer at a customer site. If Murphy can bite, it will ;-) That being said, I don`t care because it is a requirement of our design to specify a unique name for each computer we ship. But I`m told some people are concerned . -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 12:41 À : general-networking Objet : RE: default hostname Given that the top 3 bytes are manufacturer ID, using all six really wouldn't make much difference unless you have the same bottom 3 bytes from the different manufacturers which is somewhat unlikely. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 5:55 AM To: general-networking Subject: default hostname Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique? _______________________________________________ General http://community.qnx.com/sf/go/post61988 _______________________________________________ General http://community.qnx.com/sf/go/post62069
You should keep in mind that qnet really has no right to be changing the hostname. I put that hack in there as kind of an emergency backup to make qnet work in case people didn't correctly configure their systems with proper hostnames. You really shouldn't be relying on emergency backups as part of your normal ops. Would you drive around with no front brakes in you car, hoping that you emergency handbrake on the rear drums would do the job? Anyways, the odds of having two boards with the same lower 3 bytes is right up there with me winning the lottery next week, and I've never purchased a lottery ticket in my life :) -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 10:10 AM To: general-networking Subject: RE: default hostname Unlikely but possible. I`d prefer not having to worry if in 10 years from now we need to swap a computer at a customer site. If Murphy can bite, it will ;-) That being said, I don`t care because it is a requirement of our design to specify a unique name for each computer we ship. But I`m told some people are concerned . -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 12:41 À : general-networking Objet : RE: default hostname Given that the top 3 bytes are manufacturer ID, using all six really wouldn't make much difference unless you have the same bottom 3 bytes from the different manufacturers which is somewhat unlikely. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 5:55 AM To: general-networking Subject: default hostname Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique? _______________________________________________ General http://community.qnx.com/sf/go/post61988 _______________________________________________ General http://community.qnx.com/sf/go/post62069 _______________________________________________ General http://community.qnx.com/sf/go/post62085
For sake of argumentation: I have never seen anywhere in the documentation that giving a hostname other the one generated automatically is a requirement for reliability. Funny, I find that by using three bytes only, qnet is relying on emergency handbrake. -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 13:23 À : general-networking Objet : RE: default hostname You should keep in mind that qnet really has no right to be changing the hostname. I put that hack in there as kind of an emergency backup to make qnet work in case people didn't correctly configure their systems with proper hostnames. You really shouldn't be relying on emergency backups as part of your normal ops. Would you drive around with no front brakes in you car, hoping that you emergency handbrake on the rear drums would do the job? Anyways, the odds of having two boards with the same lower 3 bytes is right up there with me winning the lottery next week, and I've never purchased a lottery ticket in my life :) -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 10:10 AM To: general-networking Subject: RE: default hostname Unlikely but possible. I`d prefer not having to worry if in 10 years from now we need to swap a computer at a customer site. If Murphy can bite, it will ;-) That being said, I don`t care because it is a requirement of our design to specify a unique name for each computer we ship. But I`m told some people are concerned . -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 12:41 À : general-networking Objet : RE: default hostname Given that the top 3 bytes are manufacturer ID, using all six really wouldn't make much difference unless you have the same bottom 3 bytes from the different manufacturers which is somewhat unlikely. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 5:55 AM To: general-networking Subject: default hostname Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique? _______________________________________________ General http://community.qnx.com/sf/go/post61988 _______________________________________________ General http://community.qnx.com/sf/go/post62069 _______________________________________________ General http://community.qnx.com/sf/go/post62085 _______________________________________________ General http://community.qnx.com/sf/go/post62092
Qnet relies on each host having a unique hostname, for database indexing purposes. It should be documented. You should configure your hosts with unique hostnames. You should not rely upon this hack in Qnet. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 10:36 AM To: general-networking Subject: RE: default hostname For sake of argumentation: I have never seen anywhere in the documentation that giving a hostname other the one generated automatically is a requirement for reliability. Funny, I find that by using three bytes only, qnet is relying on emergency handbrake. -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 13:23 À : general-networking Objet : RE: default hostname You should keep in mind that qnet really has no right to be changing the hostname. I put that hack in there as kind of an emergency backup to make qnet work in case people didn't correctly configure their systems with proper hostnames. You really shouldn't be relying on emergency backups as part of your normal ops. Would you drive around with no front brakes in you car, hoping that you emergency handbrake on the rear drums would do the job? Anyways, the odds of having two boards with the same lower 3 bytes is right up there with me winning the lottery next week, and I've never purchased a lottery ticket in my life :) -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 10:10 AM To: general-networking Subject: RE: default hostname Unlikely but possible. I`d prefer not having to worry if in 10 years from now we need to swap a computer at a customer site. If Murphy can bite, it will ;-) That being said, I don`t care because it is a requirement of our design to specify a unique name for each computer we ship. But I`m told some people are concerned . -----Message d'origine----- De : Andrew Boyd [mailto:community-noreply@qnx.com] Envoyé : 6 août 2010 12:41 À : general-networking Objet : RE: default hostname Given that the top 3 bytes are manufacturer ID, using all six really wouldn't make much difference unless you have the same bottom 3 bytes from the different manufacturers which is somewhat unlikely. -- aboyd ________________________________ From: Mario Charest [mailto:community-noreply@qnx.com] Sent: Fri 8/6/2010 5:55 AM To: general-networking Subject: default hostname Default hostname is generated using the last 3 bytes of the MAC address. Wouldn`t it be safer to use all 6 bytes given that qnet goes offline if the hostname/domain isn`t unique? _______________________________________________ General http://community.qnx.com/sf/go/post61988 _______________________________________________ General http://community.qnx.com/sf/go/post62069 _______________________________________________ General http://community.qnx.com/sf/go/post62085 _______________________________________________ General http://community.qnx.com/sf/go/post62092 _______________________________________________ General http://community.qnx.com/sf/go/post62096
