dhcpcd-discuss

Hi Sven

On 26/12/16 15:16, Sven Kirmess wrote:
> My firewall runs LEAF Bering-uClibc 6.0.0, which comes with dhcpcd
> 6.11.5. Most of the time IPv6 is working, but from time to time I have
> the following really strange problem. The PPPoE connection is
> established (with +ipv6 in /etc/ppp/options). But whenever I start the
> dhcpcd, which should obtain IPv6 adresses through DHCPv6-PD, the
> connection gets terminated.
> 
> From the logs it looks like the ISP terminates the connection (LCP
> terminated by peer) because it wasn't able to serve me an IPv6 range
> (DHCPv6 REPLY: NOPREFIX-AVAIL).
> 
> Does that make sense?
> 
> Is that a problem with my ISP?
> 
> Or is that a problem on my side? The problem started after I've rebooted
> the firewall. Does dhcpcd store a lease file somewhere that, maybe, did
> not survive the reboot?

I would say that it's a problem with your ISP - they dropped the link
and dhcpcd just reacted to it.

> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.100: IAID b9:40:7f:ee
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.100: IAID conflicts with one
> assigned to em2.170
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.170: IAID b9:40:7f:ee
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.170: IAID conflicts with one
> assigned to em2.100
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.191: IAID b9:40:7f:ee
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.191: IAID conflicts with one
> assigned to em2.100
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.192: IAID b9:40:7f:ee
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.192: IAID conflicts with one
> assigned to em2.100
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.193: IAID b9:40:7f:ee
> Dec 25 02:26:55 kaldra dhcpcd[9083]: em2.193: IAID conflicts with one
> assigned to em2.100

But we should fix this :)

> /etc/dhcpcd.conf:
> 
> debug
> ipv6only
> duid
> option rapid_commit
> option domain_name_servers
> nohook hostname, resolv.conf, mtu, wpa_supplicant, timezone, lookup-hostname
> allowinterfaces ppp0 em2.100 em2.170 em2.191 em2.192 em2.193
> noipv6rs
> background
> timeout 0
> interface ppp0
>     ipv6rs
>     ia_pd 1/60 em2.100/4 em2.170/10 em2.191/11 em2.192/12 em2.193/13

At a guess, em2 is the same interface and the .NNN is a VLAN identifier?
Because (from a DHCP perspective) they are different interfaces we need
to ensure they have different IAIDs .... because they are based on MAC
address by default this won't work with VLAN. As there is currently no
VLAN detection code in dhcpcd (this could be argued as a bug, feel free
to file a ticket so we could automate this) we need to manually assign them.

interface em2.100
	iaid 2100
interface em2.170
	iaid 2170
interface em2.191
	iaid 2191
interface em2.192
	iaid 2192
interface em2.193
	iaid 2193

That should eliminate the warnings, but won't fix the PPPoE disconnect
issue.

Roy