nanog mailing list archives
Re: Content Delivery Networks
From: Rodney Joffe <rjoffe () centergate com>
Date: Fri, 10 Aug 2007 07:52:02 -0700
On Aug 9, 2007, at 10:55 PM, Paul Reubens wrote:
How do you engineer around enterprise and ISP recursors that don't honor TTL, instead caching DNS records for a week or more?
In my "little" bit of research and experience over the last 10 years in this field, I have often pursued this "urban myth". It remains largely just that.
The most common supposed violator of this was AOL. I found myself in a position at one stage to get to the "root" of this, and was rather impressed to find that it was indeed a myth.
We've just finished a small research project where we looked at approximately 16 million recursive servers. The only ones violating this were some CPE devices that ran local recursive services, and they were generally along the lines of returning the appropriate TTL the first time they were queried, and if the TTL was zero, they returned a higher TTL (10000 seconds) to subsequent queries for a short period (5 minutes). It may have been a code bug, or a designed behavior given that these were CPE devices.
Do you have any real examples of significant recursive servers doing this?
Current thread:
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E, (continued)
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E Pekka Savola (Aug 03)
- RE: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E Jason J. W. Williams (Aug 03)
- Content Delivery Networks Rod Beck (Aug 06)
- Re: Content Delivery Networks Patrick W. Gilmore (Aug 06)
- Re: Content Delivery Networks Michal Krsek (Aug 07)
- Re: Content Delivery Networks Patrick W. Gilmore (Aug 07)
- Re: Content Delivery Networks Michal Krsek (Aug 07)
- Re: Content Delivery Networks Patrick W.Gilmore (Aug 07)
- Re: Content Delivery Networks Michal Krsek (Aug 07)
- Re: Content Delivery Networks Paul Reubens (Aug 09)
- Re: Content Delivery Networks Rodney Joffe (Aug 10)
- RE: Content Delivery Networks andrew2 (Aug 10)
- Re: Content Delivery Networks John Levine (Aug 10)
- Re: Content Delivery Networks Patrick W. Gilmore (Aug 10)
- Re: Content Delivery Networks Crist Clark (Aug 10)
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E Pekka Savola (Aug 03)
- Message not available
- Re: Content Delivery Networks Rodney Joffe (Aug 10)
- Re: Content Delivery Networks Chris L. Morrow (Aug 10)
- Message not available
- Re: Content Delivery Networks Chris L. Morrow (Aug 11)
- Re: Content Delivery Networks Florian Weimer (Aug 13)
- Re: Content Delivery Networks Rodney Joffe (Aug 13)
- Re: Content Delivery Networks Chris L. Morrow (Aug 13)