On Mon, Jul 27, 2015 at 08:26:08AM -0700, Assi Friedman wrote:

Addressing residential internet service with DHCP is a problem with the encap method. Does RIPv2 address this problem? Thanks, Assi

Short answer: Not really.

If you're referring to the dynamic nature of some home connections where the address may vary from hour to hour or day to day, there is no good solution to the problem.

What we have adopted as a workaround is to allow the gateway to specify a host name instead of an absolute address. That hostname is looked up and the current address of the hostname is substituted into the encap table which drives the API, RIP, and encap.txt mechanisms. By using a service such as dyndns.org to update the hostname to address mapping dynamically, gateways which experience changes in their commercial address can arrange to have their encapsulation endpoint updated soon after they get a new address.

With both RIP and encap being updated several times an hour the amount of delay is minimized, but there is a brief period of some minutes during which their gateway is unreachable because the encap table contains the old address.

People using the RIP mechanism get the updates automatically when they occur. Those using the encap.txt file can specify to have a new copy of the refreshed file mailed to them when it changes. The API generates fresh content when it is fetched, so the update rate depends on how often you fetch it. Chris tells me that the encap table is updated by a cron job as often as every 5 minutes, so presumably you could track changes as quickly as that if you wanted. - Brian