Bug 1956209 - dhclient -6 -P ppp0 does not complete prefix acquire
Summary: dhclient -6 -P ppp0 does not complete prefix acquire
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: dhcp
Version: 34
Hardware: Unspecified
OS: Unspecified
unspecified
urgent
Target Milestone: ---
Assignee: Pavel Zhukov
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2021-05-03 08:15 UTC by udo
Modified: 2021-05-04 15:29 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed:
Type: Bug


Attachments (Terms of Use)

Description udo 2021-05-03 08:15:57 UTC
Description of problem:
We use dhclient to obtain ipv6 prefix from our ISP.
We see that dhclient keeps handshaking and does not complete.


Version-Release number of selected component (if applicable):
dhcp-client-4.4.2-9.b1.fc34.x86_64

How reproducible:
Have vdsl with pppoE connection up with ISP that supports ipv6 prefix delegation.
Run `dhclient -6 -P ppp0 -d`.
See the handshake continue.
See that we do not continue beyond PREINIT6 phase by dumping environment in dhclient-exit-hooks.

Actual results:
See below.


Expected results:
Prefix acquired, BOUND6 or RENEW6 state reached.


Additional info:
# dhclient -6 -P ppp0 -d
Internet Systems Consortium DHCP Client 4.4.2b1
Copyright 2004-2019 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on Socket/ppp0
Sending on   Socket/ppp0
xid: rand init seed (0x9cfbab24) built using all available interfaces
PRC: Soliciting for leases (INIT).
XMT: Forming Solicit, 0 ms elapsed.
XMT:  X-- IA_PD 00:00:00:00
XMT:  | X-- Request renew in  +3600
XMT:  | X-- Request rebind in +5400
XMT: Solicit on ppp0, interval 1080ms.
XMT: Forming Solicit, 1080 ms elapsed.
XMT:  X-- IA_PD 00:00:00:00
XMT:  | X-- Request renew in  +3600
XMT:  | X-- Request rebind in +5400
XMT: Solicit on ppp0, interval 2220ms.
XMT: Forming Solicit, 3300 ms elapsed.
XMT:  X-- IA_PD 00:00:00:00
XMT:  | X-- Request renew in  +3600
XMT:  | X-- Request rebind in +5400
XMT: Solicit on ppp0, interval 4240ms.
XMT: Forming Solicit, 7550 ms elapsed.
XMT:  X-- IA_PD 00:00:00:00
XMT:  | X-- Request renew in  +3600
XMT:  | X-- Request rebind in +5400
XMT: Solicit on ppp0, interval 8330ms.
^C

At similar time ran tcpdump:

# tcpdump -i ppp0 -v port 546
dropped privs to tcpdump
tcpdump: listening on ppp0, link-type LINUX_SLL (Linux cooked v1), snapshot length 262144 bytes
10:07:16.692661 IP6 (flowlabel 0xf8863, hlim 1, next-header UDP (17) payload length: 60) vuurmuur.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp sum ok] dhcp6 solicit (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (option-request DNS-server DNS-search-list) (elapsed-time 0) (IA_PD IAID:0 T1:3600 T2:5400))
10:07:16.707444 IP6 (class 0xc0, hlim 64, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:16.707632 IP6 (class 0xc0, hlim 63, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:17.775036 IP6 (flowlabel 0xf8863, hlim 1, next-header UDP (17) payload length: 60) vuurmuur.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp sum ok] dhcp6 solicit (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (option-request DNS-server DNS-search-list) (elapsed-time 108) (IA_PD IAID:0 T1:3600 T2:5400))
10:07:17.794564 IP6 (class 0xc0, hlim 64, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:17.794892 IP6 (class 0xc0, hlim 63, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:19.998336 IP6 (flowlabel 0xf8863, hlim 1, next-header UDP (17) payload length: 60) vuurmuur.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp sum ok] dhcp6 solicit (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (option-request DNS-server DNS-search-list) (elapsed-time 330) (IA_PD IAID:0 T1:3600 T2:5400))
10:07:20.013191 IP6 (class 0xc0, hlim 64, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:20.013450 IP6 (class 0xc0, hlim 63, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:24.243585 IP6 (flowlabel 0xf8863, hlim 1, next-header UDP (17) payload length: 60) vuurmuur.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp sum ok] dhcp6 solicit (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (option-request DNS-server DNS-search-list) (elapsed-time 755) (IA_PD IAID:0 T1:3600 T2:5400))
10:07:24.595880 IP6 (class 0xc0, hlim 64, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
10:07:24.596120 IP6 (class 0xc0, hlim 63, next-header UDP (17) payload length: 141) fe80::9ecc:83ff:fec6:e7e5.dhcpv6-server > vuurmuur.dhcpv6-client: [udp sum ok] dhcp6 advertise (xid=6fd0c0 (client-ID hwaddr/time type 1 time 394565497 004063f60200) (server-ID vid 0000058339633a63) (IA_PD IAID:0 T1:3600 T2:5760 (IA_PD-prefix 2001:981:a812::/48 pltime:7200 vltime:7200)) (DNS-server resolver.xs4all.nl resolver.xs4all.nl))
^C

Comment 1 udo 2021-05-03 09:18:56 UTC
BTW:

`man 8 dhclient-script` does not really mention the ipv6 cases, dhclient.d, etc.

Comment 2 udo 2021-05-03 14:18:51 UTC
firewall off does not matter.
We do have active VDSL connection, indicated by ipv4 ping.

Comment 3 udo 2021-05-04 15:29:57 UTC
Questions that come to mind:

What is unacceptable in the dhcp-server responses that apparently reach dhclient? (see `strace`)
Why isn't this logged? It would be helpful to know what is wrong...
Why doesn't -v help here?
How to debug this?


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