Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
On 22/07/14 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com Hello Mark, add dot at the end of SRV target. ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com. DNS server is adding 'example.com.' to all non-FQDN domain names which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. Thank you very much, -m -- Red Hat Reference Architectures Follow Us:https://twitter.com/RedHatRefArch Plus Us:https://plus.google.com/u/0/b/114152126783830728030/ Like Us:https://www.facebook.com/rhrefarch -- Martin Basti -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
On 22.7.2014 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, I don't think so :-) Please note the trailing dot in target part of http://en.wikipedia.org/wiki/SRV_record#Record_format. IPA behaves in the same way as BIND 9: All domain names without trailing dot are automatically extended with zone origin, i.e. example.com.. You have two options: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1 (DNS server will automatically append example.com.) or # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com. (please note the trailing dot) Another note is about _foo. foo should be service name according to http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml It will probably not cause any problems if you invent your own name (preferably prefixed with x- to avoid collisions in future, e.g. _x-foo), but it will not hurt you if you register your protocol into the registry :-) See http://tools.ietf.org/html/rfc6335 and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. What are you trying to achieve? The port number refers to port used by your application, not to DNS. -- Petr^2 Spacek -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
On 22/07/14 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. ^^ Is this typo, or the host command really returns two dots? Martin In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. Thank you very much, -m -- Red Hat Reference Architectures Follow Us:https://twitter.com/RedHatRefArch Plus Us:https://plus.google.com/u/0/b/114152126783830728030/ Like Us:https://www.facebook.com/rhrefarch -- Martin Basti -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
Martin, Petr, I didn't see that missing dot . - good catch. As always the devil is in the details :-) Two follow up questions: 1. I've set the priority and weighting equally here but I will add a third host so would it make sense to just set both priority and weight to 0 for all three hosts?: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo1.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo2.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo3.example.com. 2. To Petr's point about registering the _foo.tcp service. By definition this isn't really a true service and more like CNAME with benefits. (Sorry, couldn't resist the bad dating reference ;-)) Do I actually still need to add this to /etc/services? If so, then I'd have to do that for all hosts in the environment, IdM servers, clients, etc., correct? Truth be told, this is just being used for an alternative to a true h/w, s/w load balancer for demonstration purposes so I'm sure adding it to the services file makes sense. Thank you both! -m On 07/22/2014 03:16 AM, Petr Spacek wrote: On 22.7.2014 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, I don't think so :-) Please note the trailing dot in target part of http://en.wikipedia.org/wiki/SRV_record#Record_format. IPA behaves in the same way as BIND 9: All domain names without trailing dot are automatically extended with zone origin, i.e. example.com.. You have two options: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1 (DNS server will automatically append example.com.) or # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com. (please note the trailing dot) Another note is about _foo. foo should be service name according to http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml It will probably not cause any problems if you invent your own name (preferably prefixed with x- to avoid collisions in future, e.g. _x-foo), but it will not hurt you if you register your protocol into the registry :-) See http://tools.ietf.org/html/rfc6335 and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. What are you trying to achieve? The port number refers to port used by your application, not to DNS. -- Red Hat Reference Architectures Follow Us: https://twitter.com/RedHatRefArch Plus Us: https://plus.google.com/u/0/b/114152126783830728030/ Like Us: https://www.facebook.com/rhrefarch -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
On 07/22/2014 08:00 AM, Mark Heslin wrote: Martin, Petr, I didn't see that missing dot . - good catch. As always the devil is in the details :-) Two follow up questions: 1. I've set the priority and weighting equally here but I will add a third host so would it make sense to just set both priority and weight to 0 for all three hosts?: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo1.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo2.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo3.example.com. 2. To Petr's point about registering the _foo.tcp service. By definition this isn't really a true service and more like CNAME with benefits. (Sorry, couldn't resist the bad dating reference ;-)) Do I actually still need to add this to /etc/services? If so, then I'd have to do that for all hosts in the environment, IdM servers, clients, etc., correct? Truth be told, this is just being used for an alternative to a true h/w, s/w load balancer for demonstration purposes so I'm sure adding it to the services file makes sense. Gah! I meant to say I'm *not* sure adding it to the services file makes sense. Thank you both! -m On 07/22/2014 03:16 AM, Petr Spacek wrote: On 22.7.2014 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, I don't think so :-) Please note the trailing dot in target part of http://en.wikipedia.org/wiki/SRV_record#Record_format. IPA behaves in the same way as BIND 9: All domain names without trailing dot are automatically extended with zone origin, i.e. example.com.. You have two options: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1 (DNS server will automatically append example.com.) or # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com. (please note the trailing dot) Another note is about _foo. foo should be service name according to http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml It will probably not cause any problems if you invent your own name (preferably prefixed with x- to avoid collisions in future, e.g. _x-foo), but it will not hurt you if you register your protocol into the registry :-) See http://tools.ietf.org/html/rfc6335 and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. What are you trying to achieve? The port number refers to port used by your application, not to DNS. -- Red Hat Reference Architectures Follow Us: https://twitter.com/RedHatRefArch Plus Us: https://plus.google.com/u/0/b/114152126783830728030/ Like Us: https://www.facebook.com/rhrefarch -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
Re: [Freeipa-users] Correct syntax for round-robin DNS srv records
On 22.7.2014 14:06, Mark Heslin wrote: On 07/22/2014 08:00 AM, Mark Heslin wrote: Martin, Petr, I didn't see that missing dot . - good catch. As always the devil is in the details :-) Two follow up questions: 1. I've set the priority and weighting equally here but I will add a third host so would it make sense to just set both priority and weight to 0 for all three hosts?: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo1.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo2.example.com. # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 0 53 foo3.example.com. 2. To Petr's point about registering the _foo.tcp service. By definition this isn't really a true service and more like CNAME with benefits. (Sorry, couldn't resist the bad dating reference ;-)) Do I actually still need to add this to /etc/services? If so, then I'd have to do that for all hosts in the environment, IdM servers, clients, etc., correct? Truth be told, this is just being used for an alternative to a true h/w, s/w load balancer for demonstration purposes so I'm sure adding it to the services file makes sense. Gah! I meant to say I'm *not* sure adding it to the services file makes sense. For test purposes you can use whatever, preferably something like _x-test. No modification to /etc/services is necessary. AFAIK /etc/services just allows clients to translate service name to port number but this will not be used anyway because clients will get port number from DNS. Petr^2 Spacek Thank you both! -m On 07/22/2014 03:16 AM, Petr Spacek wrote: On 22.7.2014 00:13, Mark Heslin wrote: Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, I don't think so :-) Please note the trailing dot in target part of http://en.wikipedia.org/wiki/SRV_record#Record_format. IPA behaves in the same way as BIND 9: All domain names without trailing dot are automatically extended with zone origin, i.e. example.com.. You have two options: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1 (DNS server will automatically append example.com.) or # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com. (please note the trailing dot) Another note is about _foo. foo should be service name according to http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml It will probably not cause any problems if you invent your own name (preferably prefixed with x- to avoid collisions in future, e.g. _x-foo), but it will not hurt you if you register your protocol into the registry :-) See http://tools.ietf.org/html/rfc6335 and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. What are you trying to achieve? The port number refers to port used by your application, not to DNS. -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
[Freeipa-users] Correct syntax for round-robin DNS srv records
Hi All, I had some off-list exchanges with Petr Spacek on this but am still trying to work out the correct syntax. I have 2 hosts: - foo1.example.com - foo2.example.com and would like to create a round-robin DNS srv record for both called foo.example.com I already have DNS entries for both hosts in IPA: # ipa dnsrecord-show example.com foo1 Record name: foo1 A record: 10.0.0.1 # ipa dnsrecord-show example.com foo2 Record name: foo2 A record: 10.0.0.2 I'd like to get the correct syntax for adding the srv record for foo. My understanding is that it should be something like this: # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo1.example.com Record name: _foo.tcp SRV record: 0 50 53 foo1.example.com # ipa dnsrecord-add example.com _foo.tcp --srv-rec=0 50 53 foo2.example.com Record name: _foo.tcp SRV record: 0 50 53 foo2.example.com which seemed to be added ok but on second glance I think not: # host -t srv _foo.tcp.example.com _foo.tcp..example.com has SRV record 0 50 53 foo1.example.com.example.com. _foo.tcp..example.com has SRV record 0 50 53 foo2.example.com.example.com. In looking over the description of rfc2782 http://en.wikipedia.org/wiki/SRV_record it appears the IPA syntax is a little different, and the documentation is scarce so admittedly I'm taking a swag at this ;-) I can do this fine without srv but don't have enough familiarity with DNS srv here. Can anyone help clarify what I'm missing? I'd like to have equal weighting, priority to both hosts - I'm assuming the port (53) is correct for DNS here as well. Thank you very much, -m -- Red Hat Reference Architectures Follow Us: https://twitter.com/RedHatRefArch Plus Us: https://plus.google.com/u/0/b/114152126783830728030/ Like Us: https://www.facebook.com/rhrefarch -- Manage your subscription for the Freeipa-users mailing list: https://www.redhat.com/mailman/listinfo/freeipa-users Go To http://freeipa.org for more info on the project
