Ubuntu 16.04

Mikael Abrahamsson swmike at swm.pp.se
Fri Apr 22 14:37:37 CEST 2016


On Fri, 22 Apr 2016, Jeroen Massar wrote:

> Isn't it awesome that Ubuntu wants dynamic addresses on servers? :)

Well, this wasn't a server, this is installed as a desktop.

> They have been told about that problem by many people already,
> unfortunately, they claim to know better...

Who are "they"?

> But, check your 'sysctl -a | net.ipv6.conf' you might find some knobs
> there. Next to that, check systemd settings as that thing wants to take
> over the kernel and thus ignores those settings and comes up with it's
> own...

It's strangem it looks like they still have the kernel to process RAs? 
Doesn't it seem like the kernel now has support for the kind of stable 
non-EUI64 based addresses from https://tools.ietf.org/html/rfc7217 ?

http://unix.stackexchange.com/questions/251401/cannot-read-key-net-ipv6-conf-all-stable-secret-in-sysctl 
seems to indicate that the error message below is because the secret isn't 
set? So potentially if I set the secret I'll get the same address every 
time? Let's try...

$ sudo sysctl -a | grep net.ipv6.conf | grep -i eth0
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.eth0.stable_secret"
net.ipv6.conf.eth0.accept_dad = 1
net.ipv6.conf.eth0.accept_ra = 1
net.ipv6.conf.eth0.accept_ra_defrtr = 0
net.ipv6.conf.eth0.accept_ra_from_local = 0
net.ipv6.conf.eth0.accept_ra_min_hop_limit = 1
net.ipv6.conf.eth0.accept_ra_mtu = 1
net.ipv6.conf.eth0.accept_ra_pinfo = 0
net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.eth0.accept_ra_rtr_pref = 0
net.ipv6.conf.eth0.accept_redirects = 1
net.ipv6.conf.eth0.accept_source_route = 0
net.ipv6.conf.eth0.autoconf = 1
net.ipv6.conf.eth0.dad_transmits = 1
net.ipv6.conf.eth0.disable_ipv6 = 0
net.ipv6.conf.eth0.force_mld_version = 0
net.ipv6.conf.eth0.force_tllao = 0
net.ipv6.conf.eth0.forwarding = 0
net.ipv6.conf.eth0.hop_limit = 64
net.ipv6.conf.eth0.ignore_routes_with_linkdown = 0
net.ipv6.conf.eth0.max_addresses = 16
net.ipv6.conf.eth0.max_desync_factor = 600
net.ipv6.conf.eth0.mc_forwarding = 0
net.ipv6.conf.eth0.mldv1_unsolicited_report_interval = 10000
sysctl: reading key "net.ipv6.conf.lo.stable_secret"
sysctl: reading key "net.ipv6.conf.wlan0.stable_secret"
net.ipv6.conf.eth0.mldv2_unsolicited_report_interval = 1000
net.ipv6.conf.eth0.mtu = 1500
net.ipv6.conf.eth0.ndisc_notify = 0
net.ipv6.conf.eth0.proxy_ndp = 0
net.ipv6.conf.eth0.regen_max_retry = 3
net.ipv6.conf.eth0.router_probe_interval = 60
net.ipv6.conf.eth0.router_solicitation_delay = 1
net.ipv6.conf.eth0.router_solicitation_interval = 4
net.ipv6.conf.eth0.router_solicitations = 3
net.ipv6.conf.eth0.suppress_frag_ndisc = 1
net.ipv6.conf.eth0.temp_prefered_lft = 86400
net.ipv6.conf.eth0.temp_valid_lft = 604800
net.ipv6.conf.eth0.use_oif_addrs_only = 0
net.ipv6.conf.eth0.use_tempaddr = 2


-- 
Mikael Abrahamsson    email: swmike at swm.pp.se


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