#4722 IPv6 listen problems

[johann]

first, the servers had IPv6 listening removed due to a re-config taking the base IPv6 delegation out to /64. IPv6 is purely for emergency remote access since all regular access is via ssh tunnel with WM listening on 127.0.0.1.
second, trying to add back IPv6 listening created two (2) problems.
an example of the server specs:
# root@2secure.us Mon Mar 14 13:13:33 / (24 @ 116,340 bytes) OK # datef;echoe "\nSYSTEM:";uname -a;echoe "\nWEBMIN IPv6:";ip addr show|grep ":2692";dig +short aaaa wm6.s0.forthepolls.org;ping6 -c1 2604:4300:000a:0113:1000:0000:0000:2692;echoe "\nPERL:";yum list perl perl-Socket6\*;echo
2016.MAR.14 13:13:37 -07:00 PDT
SYSTEM:

• Linux 2secure.us 2.6.32-573.el6.x86_64 #1 SMP Thu Jul 23 15:44:03 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

WEBMIN IPv6:

• inet6 2604:4300:a:113:1000::2692/128 scope global
• 2604:4300:a:113:1000::2692
• PING 2604:4300:000a:0113:1000:0000:0000:2692(2604:4300🅰️113:1000::2692) 56 data bytes
• 64 bytes from 2604:4300:a:113:1000::2692: icmp_seq=1 ttl=64 time=0.042 ms
• --- 2604:4300:000a:0113:1000:0000:0000:2692 ping statistics ---
• 1 packets transmitted, 1 received, 0% packet loss, time 0ms
• rtt min/avg/max/mdev = 0.042/0.042/0.042/0.000 ms

PERL:

• Loaded plugins: security
• Installed Packages
• perl.x86_64 4:5.10.1-141.el6_7.1 @PUIAS_6_core_Updates
• perl-Socket6.x86_64 0.23-4.el6 @PUIAS_6_core_Base
• perl-Socket6-debuginfo.x86_64 0.23-4.el6 @cr

PROBLEM ONE:
the bean-counter in me makes me use full 4-byte fields for all eight (8) IPv6 fields so i can immediately know what i am seeing and all IP's nicely line up. in the Webmin Configuration -> Ports and Addresses dialogue if you enter the full IPv6 addr (non-compacted) it seems webmin is doing a compare against some util such as 'ip' and rejects the IP as input even though it exists. to wit:
'Failed to change address : The IP address 2604:4300:000a:0113:1000:0000:0000:2692 is not active on this system, and so cannot be used.'
as can be plainly observed from the in-/out-put, supra, the normal linux util's work just fine with the IPv6 as defined for 'bind':

• wm6.s0 IN AAAA 2604:4300:000a:0113:1000:0000:0000:2692
  and in 'ifcfg-eth0':

* IPV6ADDR_SECONDARIES=" \
*                 ...
*  2604:4300:000a:0113:1000:0000:0000:2692/128 \
*                  ..."

PROBLEM TWO:
the work-around for PROBLEM ONE is to use the compacted IPv6 addr. however, in 1.791 a different problem pops up after one does that re 'perl-Socket6'. to wit:

• 'Failed to change address : IPv6 cannot be enabled unless the Socket6 Perl module is installed'
  as can be seen, supra, the 'perl-Socket6' is installed.

i am not sure when webmin started to have these problems since it has been a while (and probably several up-dates ago) since i had IPv6 configured in webmin.

[Jamie Cameron]

Problem 1 - this will be fixed in the next Webmin release.

Problem 2 - if you SSH into your system and run perl -e "use Socket6" , what error do you get?

[johann]

perl [-[wW]] -[eE] "use Socket6" --> no output
perl -c [-[wW]] -[eE] "use Socket6" --> '-e syntax OK'

Thank you,

Johann

On 2016.Mar.14 23:05, Jamie Cameron wrote:

|perl -e "use Socket6"|
yum list installed perl perl*

perl.x86_64
4:5.10.1-141.el6_7.1 @PUIAS_6_core_Updates
perl-Bit-Vector.x86_64
7.1-2.el6 @PUIAS_6_core_Base
perl-CPAN.x86_64
1.9402-141.el6_7.1 @PUIAS_6_core_Updates
perl-Carp-Clan.noarch
6.03-2.el6 @PUIAS_6_core_Base
perl-DBD-MySQL.x86_64
4.013-3.el6 @PUIAS_6_core_Base
perl-DBI.x86_64
1.609-4.el6 @PUIAS_6_core_Base
perl-Date-Calc.noarch
6.3-2.el6 @PUIAS_6_core_Base
perl-Digest-SHA.x86_64
1:5.47-141.el6_7.1 @PUIAS_6_core_Updates
perl-ExtUtils-MakeMaker.x86_64
6.55-141.el6_7.1 @PUIAS_6_core_Updates
perl-ExtUtils-ParseXS.x86_64
1:2.2003.0-141.el6_7.1 @PUIAS_6_core_Updates
perl-JSON-XS.x86_64
1:2.27-2.el6 @epel
perl-Module-Pluggable.x86_64
1:3.90-141.el6_7.1 @PUIAS_6_core_Updates
perl-Net-SSLeay.x86_64
1.35-9.el6 @PUIAS_6_core_Base
perl-Pod-Escapes.x86_64
1:1.04-141.el6_7.1 @PUIAS_6_core_Updates
perl-Pod-Simple.x86_64
1:3.13-141.el6_7.1 @PUIAS_6_core_Updates
perl-Socket6.x86_64
0.23-4.el6 @PUIAS_6_core_Base
perl-Socket6-debuginfo.x86_64
0.23-4.el6 @cr
perl-Test-Harness.x86_64
3.17-141.el6_7.1 @PUIAS_6_core_Updates
perl-Time-HiRes.x86_64
4:1.9721-141.el6_7.1 @PUIAS_6_core_Updates
perl-WWW-Curl.x86_64
4.09-4.el6 @PUIAS_6_core_Base
perl-YAML.noarch
0.70-4.el6 @PUIAS_6_core_Base
perl-common-sense.noarch
3.5-1.puias6 @PUIAS_6_unsupported
perl-devel.x86_64
4:5.10.1-141.el6_7.1 @PUIAS_6_core_Updates
perl-hivex.x86_64
1.3.3-4.3.el6 @PUIAS_6_core_Base
perl-libs.x86_64
4:5.10.1-141.el6_7.1 @PUIAS_6_core_Updates
perl-version.x86_64
3:0.77-141.el6_7.1 @PUIAS_6_core_Updates