On 4/17/15 3:53 PM, Roland Dobbins wrote:

On 18 Apr 2015, at 5:44, Chuck Anderson wrote:

2. Use anycast to make your multiple DNS servers appear as one IP, and
 put that one IP in /etc/resolv.conf.  You can have multiple IPs,
 but each one should still be anycasted.

The problem with using only one IP is that if someone accidentally
fat-fingers an ACL or a routing statement or a firewall rule or
whatever, all recursive DNS is hosed.

So, anycasting *two* IP addresses (on differing netblocks) is probably
warranted.

IME the behavior in failover to a secondary resolver address is so troublesome that if you're going to go to the trouble of anycasting (or load balancing) a resolver address it's better to go with just one.

In the unlikely event that someone does what you describe Roland (i.e., fat-finger access to a core services network), you're going to have so many other problems that resolver failover is going to be the least of your worries.

FWIW,

Doug

--
I am conducting an experiment in the efficacy of PGP/MIME signatures. This message should be signed. If it is not, or the signature does not validate, please let me know how you received this message (direct, or to a list) and the mail software you use. Thanks!

Attachment: signature.asc
Description: OpenPGP digital signature

_______________________________________________
dns-operations mailing list
[email protected]
https://lists.dns-oarc.net/mailman/listinfo/dns-operations
dns-jobs mailing list
https://lists.dns-oarc.net/mailman/listinfo/dns-jobs

Reply via email to