[sr-dev] Dispatcher reverse lookup by IP

[Olle E. Johansson]

On 11 Dec 2014, at 16:12, Olle E. Johansson <oej at edvina.net> wrote:

> 
> On 11 Dec 2014, at 16:01, Olle E. Johansson <oej at edvina.net> wrote:
> 
>> Hi!
>> 
>> Digging through the dispatcher source code I think this is the way IP matching works:
>> 
>> * When loading or reloading dispatcher, hostnames are looked up to IP
>> 
>> * When running a reverse check in dispatcher the IP address is checked against $si
>> 
>> I don't understand if we handle DNS TTL and re-lookup the name here. Do I have to run 
>> a crontab dispatcher reload to make sure we have an up-to-date IP?
> 
> Additional discovery:
> - we run a new DNS lookup before doing the reverse matching, which is fine.
> 
> Note: If the dispatcher SIP URI does not resolve at load time, that entry
> is ignored, but dispatcher loads the rest of the table.

Further results:
- Dispatcher doesn't seem to support SRV names in reverse matching. Only IPs
- Dispatcher doesn't seem to support DNS names that only has SRV records in the URI at all.

I haven't tested if the reverse matching supports dual stack, but the code seems to indicate that it does.

/O