Re: rtadvd appears to ignore options set in /etc/rtadvd.conf

From: Karl Denninger <karl_at_denninger.net>
Date: Thu, 24 Jul 2025 11:47:14 UTC
Nope -- no change:

07:44:23.810602 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 
56) fe80::2e0:b4ff:fe68:f895 > ff02::1: [icmp6 sum ok] ICMP6, router 
advertisement, length 56
         hop limit 64, Flags [none], pref medium, router lifetime 1800s, 
reachable time 0ms, retrans timer 0ms
           source link-address option (1), length 8 (1): 00:e0:b4:68:f8:95
           prefix info option (3), length 32 (4): 
2606:83c0:8000:1b00::/64, Flags [onlink, auto], valid time 2592000s, 
pref. time 604800s

Note that I cannot set an actual valid "address" in the config file 
since I have no clue what it is in advance (it comes off the delegation 
from the ISP of course)

This looks like a bug (starting rtadvd with verbose debugging on in the 
foreground doesn't log any complaints -- it looks like it just ignores 
the parameters.)

On 7/23/2025 23:26, John Hay wrote:
> Hi Karl,
>
> What if you use a = instead of the #? For example :vltime=86400:
>
> I set rdnss and dnssl using = and that works.
>
> John
>
>
> On Thu, 24 Jul 2025 at 01:38, Karl Denninger <karl@denninger.net> wrote:
>
>     On 7/23/2025 16:47, Bjoern A. Zeeb wrote:
>>     On Wed, 23 Jul 2025, Karl Denninger wrote:
>>
>>     Hi,
>>
>>     (sorry I deleted the message as the tex/only part was barely
>>     parsable).
>>
>>     Can you, for testing, try adding an
>>         addr="xxx:xxx:xxx:xxxx::":\
>>     to one of your entries and see if the behaviour changes?
>>
>>     /bz
>>
>     root@IpGw:/etc # more /etc/rtadvd.conf
>     # Set the preferred lifetime to 10 minutes on advertised prefixes.
>     # All other parameters are default.
>     #
>     default:\
>             :vltime#86400:\
>             :pltime#3600:\
>             :prefixlen#64:addr="xxx:xxx:xxx:xxxx::":
>     ix1:\
>             :vltime#86400:\
>             :pltime#3600:\
>             :prefixlen#64:addr="xxx:xxx:xxx:xxxx::":
>     ix1.4:\
>             :vltime#86400:\
>             :pltime#3600:\
>             :prefixlen#64:
>
>     No change -- the announcement is going out on ix1 from the gateway.
>
>     On machine receiving the advertisements:
>
>     19:35:49.085297 IP6 (hlim 255, next-header ICMPv6 (58) payload
>     length: 56) fe80::2e0:b4ff:fe68:f895 > ff02::1: [icmp6 sum ok]
>     ICMP6, router advertisement, length 56
>             hop limit 64, Flags [none], pref medium, router lifetime
>     1800s, reachable time 0ms, retrans timer 0ms
>               source link-address option (1), length 8 (1):
>     00:e0:b4:68:f8:95
>               prefix info option (3), length 32 (4):
>     2606:83c0:8000:1b00::/64, Flags [onlink, auto], *_valid time
>     2592000s, pref. time 604800s_*
>
>
>     -- 
>     Karl Denninger
>     karl@denninger.net
>     /The Market Ticker/
>     /[S/MIME encrypted email preferred]/
>
-- 
Karl Denninger
karl@denninger.net
/The Market Ticker/
/[S/MIME encrypted email preferred]/