[Dibbler] Script not executed initially and other questions

Daniel Kenzelmann klub.com.pl at k8n.de
Thu Nov 26 10:44:52 CET 2015

> Do you have the option of switching to a less nasty provider ? If so
> then I'd recommend that - and tell the current one why your leaving.

I don't really have an option. Basically all DSL providers in Germany do 
the same.
They charge "business" rates for a fixed IP.

In addition to that, the dynamic IP was somewhat requested and seen as a 
positive thing by users (by german data retention law ISPs are not 
allowed to store data that they don't need for charging, so if you have 
a flatrate they are basically only allowed to know the current IP, not 
the previous IPs with dates. Although politicians are actively trying to 
change the law to force them to store that and more data)
That also explains why they would go through the hassle of having a 
dynamic IPv6 address prefix (users wanted that ...).

Regarding the IP renewal, as the PPPoE connection itself is terminated 
after 24hours, the new IP is issued during the beginning of the new PPP 
connection (the same with the IPv6 address, however that is only a 
link-local address, so I still need dibbler for the prefix which is also 
changing after every reconnect)

I currently have a "working" solution.
1. Connect ppp with ipv6 (getting a link-local address)
2. sysctl -w net.ipv6.conf.ppp0.accept_ra=2  to get a public IP on ppp0
3. Start dibbler, do a polling loop on the generated radvd.conf to see 
whether a prefix was obtained.
4. Use that prefix and put it into my custom radvd.conf which also 
contains another prefix for a unique local network 
(https://en.wikipedia.org/wiki/Unique_local_address) and my internal 
nameserver as RDNSS so I can still reach everything inside my network if 
the DSL connection is down.
5. restart radvd

I just think that (3) seems a bit unelegant (having to extract the 
prefix from the generated radvd.conf instead of dibbler executing a 
script that also gets the prefixes in some way (variable/parameter))

More information about the Dibbler mailing list