azec-pdx's questions

I am creating VPS solution and currently network policy for Virtual Machines provisioning provides each VM with one public IPv4 address from the reserved pool of 255 addresses. I will need to provide SSH access to these virtual machines. My SSH access creating scenario will configure each VM with SSH keys and e-mail users with required info.

I was told that it is not really recommended to provide each VM with public IP with direct SSH port opened. Instead I was advised to map all VMs to one public IP, and then open (I assume multiple) ports for SSH access to these.

How would I accomplish this? Firewall with port forwarding?

Kind Regards

I am using provider mail hosting to send emails. On my Webserver I also have Postfix running and configured. Here is my main.cf

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = yes
readme_directory = no
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
myhostname = 2-5-8.bih.net.ba
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = bhcom.info, 2-5-8.bih.net.ba, localhost.bih.net.ba, localhost
relayhost = 
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_command = 
mailbox_size_limit = 10485760
recipient_delimiter = +
inet_interfaces = 80.65.85.114

When I try sending email to my hosted domain name, every message gets bounced with this error:

Nov  4 20:38:34 2-5-8 postfix/pickup[802]: 1492A3E0C6C: uid=0 from=<[email protected]>
Nov  4 20:38:34 2-5-8 postfix/cleanup[988]: 1492A3E0C6C: message-id=<[email protected]>
Nov  4 20:38:34 2-5-8 postfix/qmgr[803]: 1492A3E0C6C: from=<[email protected]>, size=348, nrcpt=1 (queue active)
Nov  4 20:38:34 2-5-8 postfix/local[990]: 1492A3E0C6C: to=<[email protected]>, relay=local, delay=0.12, delays=0.08/0.01/0/0.04, dsn=5.1.1, status=bounced (unknown user: "info")
Nov  4 20:38:34 2-5-8 postfix/cleanup[988]: 28ED53E0C6D: message-id=<[email protected]>
Nov  4 20:38:34 2-5-8 postfix/qmgr[803]: 28ED53E0C6D: from=<>, size=2056, nrcpt=1 (queue active)
Nov  4 20:38:34 2-5-8 postfix/bounce[991]: 1492A3E0C6C: sender non-delivery notification: 28ED53E0C6D
Nov  4 20:38:34 2-5-8 postfix/qmgr[803]: 1492A3E0C6C: removed
Nov  4 20:38:34 2-5-8 postfix/local[990]: 28ED53E0C6D: to=<[email protected]>, relay=local, delay=0.06, delays=0.03/0/0/0.02, dsn=5.1.1, status=bounced (unknown user: "razvoj")
Nov  4 20:38:34 2-5-8 postfix/qmgr[803]: 28ED53E0C6D: removed

However, when I try to @gmail.com, it sends message without problems, and here is log. What might be the issue?

Nov  4 20:41:23 2-5-8 postfix/pickup[802]: B2EC63E0C6C: uid=0 from=<[email protected]>
Nov  4 20:41:23 2-5-8 postfix/cleanup[1022]: B2EC63E0C6C: message-id=<[email protected]>
Nov  4 20:41:23 2-5-8 postfix/qmgr[803]: B2EC63E0C6C: from=<[email protected]>, size=350, nrcpt=1 (queue active)
Nov  4 20:41:23 2-5-8 postfix/smtp[1024]: connect to gmail-smtp-in.l.google.com[2a00:1450:4001:c02::1a]:25: Network is unreachable
Nov  4 20:41:24 2-5-8 postfix/smtp[1024]: B2EC63E0C6C: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[173.194.70.26]:25, delay=0.97, delays=0.08/0.01/0.27/0.62, dsn=2.0.0, status=sent (250 2.0.0 OK 1352058066 f7si2180442eeo.46)
Nov  4 20:41:24 2-5-8 postfix/qmgr[803]: B2EC63E0C6C: removed

I am trying to install Net:SSH2 Perl module, but I run in this error:

[root@script-server fmzbih_cms_weather_updater]# cpanm Net::SSH2
--> Working on Net::SSH2
Fetching http://www.cpan.org/authors/id/R/RK/RKITOVER/Net-SSH2-0.44.tar.gz ... OK
Configuring Net-SSH2-0.44 ... OK
Building and testing Net-SSH2-0.44 ... FAIL
! Installing Net::SSH2 failed. See /root/.cpanm/build.log for details.
[root@script-server fmzbih_cms_weather_updater]# cat /root/.cpanm/build.log
cpanm (App::cpanminus) 1.5011 on perl 5.014002 built for i686-linux-thread-multi
Work directory is /root/.cpanm/work/1335442976.25013
You have make /usr/bin/make
You have LWP 6.04
You have /bin/tar: tar (GNU tar) 1.15.1
You have /usr/bin/unzip
Searching Net::SSH2 on cpanmetadb ...
--> Working on Net::SSH2
Fetching http://www.cpan.org/authors/id/R/RK/RKITOVER/Net-SSH2-0.44.tar.gz
-> OK
Unpacking Net-SSH2-0.44.tar.gz
Entering Net-SSH2-0.44
Checking configure dependencies from META.yml
Checking if you have ExtUtils::MakeMaker 6.59 ... Yes (6.62)
Configuring Net-SSH2-0.44
Running Makefile.PL
Subroutine checklibs redefined at inc/Module/Install/CheckLib.pm line 11.
Subroutine assertlibs redefined at inc/Module/Install/CheckLib.pm line 25.
Subroutine _author_side redefined at inc/Module/Install/CheckLib.pm line 39.

The libssh2 library is required by this module.  If you don't have it, you can
download it from http://www.libssh2.org; you may also need OpenSSL, which can be
obtained from http://www.openssl.org.

Debian:   sudo aptitude install libssh2-1-dev
OpenSUSE: sudo zypper in libssh2-1 libssh2-devel

You can pass your libssh2 lib and include dirs on the command line. E.g.:

    perl Makefile.PL lib=$HOME/libssh2/lib inc=$HOME/libssh2/include

If you want to build on Windows, see the file BUILDING.WIN32 in the
distribution.

Checking if your kit is complete...
Looks good
Writing Makefile for Net::SSH2
Writing MYMETA.yml and MYMETA.json
-> OK
Checking dependencies from MYMETA.json ...
Checking if you have ExtUtils::MakeMaker 6.59 ... Yes (6.62)
Building and testing Net-SSH2-0.44
cp lib/Net/SSH2/File.pm blib/lib/Net/SSH2/File.pm
cp lib/Net/SSH2/Dir.pm blib/lib/Net/SSH2/Dir.pm
cp lib/Net/SSH2/PublicKey.pm blib/lib/Net/SSH2/PublicKey.pm
cp lib/Net/SSH2/SFTP.pm blib/lib/Net/SSH2/SFTP.pm
cp lib/Net/SSH2/Listener.pm blib/lib/Net/SSH2/Listener.pm
cp lib/Net/SSH2/Channel.pm blib/lib/Net/SSH2/Channel.pm
cp lib/Net/SSH2.pm blib/lib/Net/SSH2.pm
AutoSplitting blib/lib/Net/SSH2.pm (blib/lib/auto/Net/SSH2)
/usr/local/bin/perl "-Iinc" /usr/local/lib/perl5/5.14.2/ExtUtils/xsubpp  -typemap /usr/local/lib/perl5/5.14.2/ExtUtils/typemap -typemap typemap  SSH2.xs > SSH2.xsc && mv SSH2.xsc SSH2.c
cc -c  -I/usr/local/include -I/usr/include -I. -D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2   -DVERSION=\"0.44\" -DXS_VERSION=\"0.44\" -fPIC "-I/usr/local/lib/perl5/5.14.2/i686-linux-thread-multi/CORE"   SSH2.c
Running Mkbootstrap for Net::SSH2 ()
chmod 644 SSH2.bs
rm -f blib/arch/auto/Net/SSH2/SSH2.so
LD_RUN_PATH="/usr/lib:/lib" cc  -shared -O2 -L/usr/local/lib -fstack-protector SSH2.o  -o blib/arch/auto/Net/SSH2/SSH2.so   \
       -L/root -L/usr/local/lib -L/lib -L/usr/lib -L/usr/local/lib -L/usr/local -L/usr/lib -L/usr -L/opt -L//lib -L/ -lssh2 -lz -lssl -lcrypto      \

/usr/bin/ld: cannot find -lz
collect2: ld returned 1 exit status
make: *** [blib/arch/auto/Net/SSH2/SSH2.so] Error 1
-> FAIL Installing Net::SSH2 failed. See /root/.cpanm/build.log for details.

Seems like I am unable to compile something due to glibc static linking. However, I don't know what's alternative for glibc-static on CentOS 5.

I am Perl beginner. I wanted to use Log::Log4perl module as I am familiar how it works in Java. I used cpanm script to download module, but I ran it without "sudo". Then it installed this module to my dir /home/amer/perl5. Afterwards, I installed it as sudoer, but I want to remove installation in my home dir to avoid any conflicts in future. How can I do that? Here is my cmdline execution stack.

Thanks and Regards!

I have following situation:

I have three clients in 3 different cities. They are all 24/7 available computer machines running in different schools and collecting energy measurements in the buildings. All three need to securely communicate with remote central database system (in 4th city) and periodically upload the data. I have the information that hardware VPN solution needs to be implemented here, but have no specification about what routers (if any) are installed on the network where database is. I also have information that DSL internet connection is available at all 3 remote measuring locations. What type of architecture, and implementation would you suggest?

Could buying of device like this be helpful? Does it matter what router is on the other side, as long as it has IPSec?

Thanks,