On Thu, Feb 22, 2024 at 10:47 AM Javier Gutierrez <GutierrezJ@westmancom.com> wrote:
I was wondering if someone had some experience with using anycast for TFTP or DHCP services?
Hi Javier, Anycast for TFTP is more or less the same as anycast for TCP-based protocols: it has corner cases which fail and fail hard, but otherwise it works. Outside the corner cases, the failure mode for tftp clients should be the same as the failure mode when the tftp server goes down in the middle of a transfer and comes back up some time later. The corner cases are variations on the theme that your routing causes packets from a particular source to oscillate between the tftp servers. In the corner cases, the tftp client can't communicate with the -same- tftp server long enough to complete a transfer. Experiments with anycast TCP suggest that the corner cases happen for less than 1% of client sources, but when they do happen tend to be persistent, affecting all communication between that client and the anycast IP address for an extended duration, sometimes weeks or months. Regards, Bill Herrin -- William Herrin bill@herrin.us https://bill.herrin.us/