Dev Blog Info

Learning about GTK apps with Vala (ElementaryOS Apps Pt 2)

February 5, 2017pavelNo Comments

Part 2 of great video from+Egee on creating Windowed application for elementary OS with Vala and GTK.

Learning about GTK apps with Vala (ElementaryOS Apps Pt 1)

February 5, 2017February 5, 2017pavelNo Comments

Great video from +Egee on creating Windowed application for elementary OS with Vala and GTK.

Become a Pro in Netstat

February 5, 2017pavelNo Comments

List all open ports with netstat -a:

$ sudo netstat -a
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 0.0.0.0:sunrpc          0.0.0.0:*               LISTEN     
tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN     
tcp        0      0 singlenode:smtp         0.0.0.0:*               LISTEN     
tcp        0      0 singlenode:ssh          gateway:60974           ESTABLISHED
tcp        0      0 singlenode:60530        ftp.eutelia.it:ftp      TIME_WAIT  
tcp        0      0 singlenode:60534        ftp.eutelia.it:ftp      TIME_WAIT  
tcp6       0      0 [::]:sunrpc             [::]:*                  LISTEN     
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN     
tcp6       0      0 localhost:smtp          [::]:*                  LISTEN     
udp        0      0 singlenode:323          0.0.0.0:*                          
udp        0      0 0.0.0.0:bootpc          0.0.0.0:*                          
udp        0      0 0.0.0.0:43911           0.0.0.0:*                          
udp6       0      0 localhost:323           [::]:*                             
udp6       0      0 [::]:15045              [::]:*                             
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags       Type       State         I-Node   Path
unix  2      [ ACC ]     STREAM     LISTENING     17312    private/local
unix  2      [ ACC ]     STREAM     LISTENING     17316    private/virtual
unix  2      [ ACC ]     STREAM     LISTENING     17319    private/lmtp
unix  2      [ ACC ]     STREAM     LISTENING     17322    private/anvil
unix  2      [ ACC ]     STREAM     LISTENING     17325    private/scache
unix  2      [ ACC ]     STREAM     LISTENING     17265    private/tlsmgr
unix  2      [ ACC ]     STREAM     LISTENING     17268    private/rewrite
...
unix  3      [ ]         STREAM     CONNECTED     17326    
unix  3      [ ]         STREAM     CONNECTED     17285    
unix  3      [ ]         STREAM     CONNECTED     17277    
unix  3      [ ]         STREAM     CONNECTED     17307    
unix  3      [ ]         STREAM     CONNECTED     17273

$ sudo netstat -a

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address Foreign Address State

tcp 0 0 0.0.0.0:sunrpc 0.0.0.0:* LISTEN

tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN

tcp 0 0 singlenode:smtp 0.0.0.0:* LISTEN

tcp 0 0 singlenode:ssh gateway:60974 ESTABLISHED

tcp 0 0 singlenode:60530 ftp.eutelia.it:ftp TIME_WAIT

tcp 0 0 singlenode:60534 ftp.eutelia.it:ftp TIME_WAIT

tcp6 0 0 [::]:sunrpc [::]:* LISTEN

tcp6 0 0 [::]:ssh [::]:* LISTEN

tcp6 0 0 localhost:smtp [::]:* LISTEN

udp 0 0 singlenode:323 0.0.0.0:*

udp 0 0 0.0.0.0:bootpc 0.0.0.0:*

udp 0 0 0.0.0.0:43911 0.0.0.0:*

udp6 0 0 localhost:323 [::]:*

udp6 0 0 [::]:15045 [::]:*

Active UNIX domain sockets (servers and established)

Proto RefCnt Flags Type State I-Node Path

unix 2 [ ACC ] STREAM LISTENING 17312 private/local

unix 2 [ ACC ] STREAM LISTENING 17316 private/virtual

unix 2 [ ACC ] STREAM LISTENING 17319 private/lmtp

unix 2 [ ACC ] STREAM LISTENING 17322 private/anvil

unix 2 [ ACC ] STREAM LISTENING 17325 private/scache

unix 2 [ ACC ] STREAM LISTENING 17265 private/tlsmgr

unix 2 [ ACC ] STREAM LISTENING 17268 private/rewrite

...

unix 3 [ ] STREAM CONNECTED 17326

unix 3 [ ] STREAM CONNECTED 17285

unix 3 [ ] STREAM CONNECTED 17277

unix 3 [ ] STREAM CONNECTED 17307

unix 3 [ ] STREAM CONNECTED 17273

List all TCP connections with netstat -at:

$ sudo netstat -at
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 0.0.0.0:sunrpc          0.0.0.0:*               LISTEN     
tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN     
tcp        0      0 singlenode:smtp         0.0.0.0:*               LISTEN     
tcp        0      0 singlenode:ssh          gateway:60974           ESTABLISHED
tcp6       0      0 [::]:sunrpc             [::]:*                  LISTEN     
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN     
tcp6       0      0 localhost:smtp          [::]:*                  LISTEN

$ sudo netstat -at

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address Foreign Address State

tcp 0 0 0.0.0.0:sunrpc 0.0.0.0:* LISTEN

tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN

tcp 0 0 singlenode:smtp 0.0.0.0:* LISTEN

tcp 0 0 singlenode:ssh gateway:60974 ESTABLISHED

tcp6 0 0 [::]:sunrpc [::]:* LISTEN

tcp6 0 0 [::]:ssh [::]:* LISTEN

tcp6 0 0 localhost:smtp [::]:* LISTEN

List all UDP connections…

CentOS 7 – Network Troubleshooting

January 21, 2017pavelNo Comments

Network troubleshooting process: Test the problem (reproduce the problem, get background information, collect logs errors and etc…) Check (get current…

CentOS 7 – Network Modify Configuration

January 18, 2017January 21, 2017pavelNo Comments

Network interface can be configured by control files of the specified interface. Those files are usually named /etc/sysconfig/network-scripts/ifcfg-<name>. Looks like:

$ cat /etc/sysconfig/network-scripts/ifcfg-ens33 
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=a207fe46-1fc2-4127-89fe-b67446730915
DEVICE=ens33
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes