Multiple CNAME alternantive?
I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. As we use many DNS servers (and or views) for our different development environments, it would be very helpful for the developers to easily find the name and IP of the proper name server to use. EXAMPLE: A lookup for dns.ourdomain.com would result in: nsdev1.ourdomain.com192.168.100.10 nsdev2.ourdomain.com192.168.100.11 nstest1.ourdomain.com 192.168.100.12 nstest2.ourdomain.com 192.168.100.13 nsprod1.ourdomain.com 192.168.100.14 nsprod2.ourdomain.com 192.168.100.15 etc. I want to avoid using configuration exceptions and multiple CNAMEs. Does anyone have a clean alternative? Thanks, Steve. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Multiple CNAME alternantive?
On 19/08/10 15:52, Steve Arntzen wrote: I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. CNAMEs are singleton; this: dns.ourdomain.com. IN CNAME nsdev1.ourdomain.com. dns.ourdomain.com. IN CNAME nsdev2.ourdomain.com. ...is illegal. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Multiple CNAME alternantive?
On 8/19/2010 10:52 AM, Steve Arntzen wrote: I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. As we use many DNS servers (and or views) for our different development environments, it would be very helpful for the developers to easily find the name and IP of the proper name server to use. EXAMPLE: A lookup for dns.ourdomain.com would result in: nsdev1.ourdomain.com192.168.100.10 nsdev2.ourdomain.com192.168.100.11 nstest1.ourdomain.com 192.168.100.12 nstest2.ourdomain.com 192.168.100.13 nsprod1.ourdomain.com 192.168.100.14 nsprod2.ourdomain.com 192.168.100.15 etc. I want to avoid using configuration exceptions and multiple CNAMEs. Does anyone have a clean alternative? If you really want a list of *names*, then you have a number of record types you could use, which have names in the RDATA part of the record, e.g. PTR, MX, SRV. PTR is probably the purest way to catalog a list of names, since it doesn't have any extraneous RDATA fields that you'd need to fill with dummy info, and also it benefits from label compression in responses. I am *not* a fan of representing hostnames in TXT records, since those don't benefit from label compression, and also, they don't prevent the accidental inclusion of extraneous characters (although those validations can be performed by whatever tool(s) maintain the data in those records). Resolver configs use IP addresses, not names. If you just want a list of *addresses*, then these can be enumerated in a round-robin A record. You can even apply sortlisting to that, if you want. - Kevin ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Multiple CNAME alternantive?
On 19/08/10 16:18, Phil Mayers wrote: On 19/08/10 15:52, Steve Arntzen wrote: I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. CNAMEs are singleton; this: dns.ourdomain.com. IN CNAME nsdev1.ourdomain.com. dns.ourdomain.com. IN CNAME nsdev2.ourdomain.com. ...is illegal. (I did try to reply to Steve's off-list post, but got: st...@arntzen.us SMTP error from remote mail server after MAIL FROM:p.may...@imperial.ac.uk: host hawkeye.arntzen.us [209.102.169.188]: 550 5.0.0 Sorry,no junk mail Huh...) Obviously I mis-read what you were asking; you want something *not* a CNAME to do this. Sorry - I, mis-read what you wanted. As Kevin mentions, perhaps PTR or SRV? The other alternative is maybe a fake sub-zone and permit AXFR. dig dns.ourdomain.com axfr ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Multiple CNAME alternantive?
On 8/19/2010 10:52 AM, Steve Arntzen wrote: I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. As we use many DNS servers (and or views) for our different development environments, it would be very helpful for the developers to easily find the name and IP of the proper name server to use. EXAMPLE: A lookup for dns.ourdomain.com would result in: nsdev1.ourdomain.com192.168.100.10 nsdev2.ourdomain.com192.168.100.11 nstest1.ourdomain.com 192.168.100.12 nstest2.ourdomain.com 192.168.100.13 nsprod1.ourdomain.com 192.168.100.14 nsprod2.ourdomain.com 192.168.100.15 etc. I don't think I'd do that in DNS. I'd point an A record for that name to a server that was running a simple web server that would spit out the list for any HTTP request, and maybe even a modified telnet daemon that would spit out the list upon a connection as well. That way your users would have a simple, relatively universal command line entry like telnet dns.example.com to use. -- Dave ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: Multiple CNAME alternantive?
On 8/19/2010 1:27 PM, Dave Sparro wrote: On 8/19/2010 10:52 AM, Steve Arntzen wrote: I would like to resolve dns.ourdomain.com to a list of our DNS server names and possibly their IPs. As we use many DNS servers (and or views) for our different development environments, it would be very helpful for the developers to easily find the name and IP of the proper name server to use. EXAMPLE: A lookup for dns.ourdomain.com would result in: nsdev1.ourdomain.com192.168.100.10 nsdev2.ourdomain.com192.168.100.11 nstest1.ourdomain.com 192.168.100.12 nstest2.ourdomain.com 192.168.100.13 nsprod1.ourdomain.com 192.168.100.14 nsprod2.ourdomain.com 192.168.100.15 etc. I don't think I'd do that in DNS. I'd point an A record for that name to a server that was running a simple web server that would spit out the list for any HTTP request, and maybe even a modified telnet daemon that would spit out the list upon a connection as well. That way your users would have a simple, relatively universal command line entry like telnet dns.example.com to use. It's a matter of personal preference, of course, but Ill point out that DNS is more lightweight than HTTP or telnet, easier to script (using the Net::DNS Perl module or gethostbyname()), and the sortlist mechanism allows for sorting a round-robin list of addresses optimally according to the source IP of the client. It's not clear to me, however, whether the OP really has a requirement to retrieve the *names* of the nameservers, or whether he just wants to fetch an optimized list of addresses to use for building a resolver config dynamically. - Kevin ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
