System Notes Org

Some of the more common tools for advanced networking include: tcpdump, netstat, wireshark, and tshark. A previous article covered Basic Linux Networking Tools . Discover Switch Information Now for the advanced stuff. We use tcpdump, and write it to a file pkt.cap. Then we use tshark to read the file. How to check the router to which the linux host is connected. # tcpdump -nvi eth0 -c 1 -s 1500 -w pkt.cap ether proto 0xaa and ether dst 01:00:0c:cc:cc:cc and ether\[20\] \=\= 0x20 and ether\[21\] \=\= 0x00 # tshark -V -r pkt.cap # tcpdump -nvi eth0 -c 1 -s 1500 -w pkt.cap ether proto 0xaa and ether dst 01:00:0c:cc:cc:cc and ether\[20\] \=\= 0x20 and ether\[21\] \=\= 0x00;tshark -V -r pkt.cap tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 1500 bytes 1 packets captured 1 packets received by filter 0 packets dropped by kernel Running as user "root" and group "root". This could be dangerous. Frame 1 (416 bytes on wire, 416 bytes captured) Arrival T...

Computers running Windows seem to have virus and spyware problems quite often. When fixing other peoples computers, I have found these free options to be very useful. Free Windows Anti Virus Software ClamWin Free Antivirus http://www.clamwin.com ClamWin is a Free Antivirus program for Microsoft Windows 7 / Vista / XP / Me / 2000 / 98 and Windows Server 2008 and 2003. avast! Free Antivirus http://www.avast.com Free Anti-Adware / Anti-Spyware Information Some of this Windows software is offered as a free version, with an option to upgrade. Generally, the free version is enough to clean any problems, but has to be run manually. Ad-Aware – check for updates, and run occasionally http://www.lavasoftusa.com Spy Bot Search and Destroy http://www.safer-networking.org Malwarebytes http://www.malwarebytes.org Malwarebyes Anti-Malware is often the best tool to remove fake anti-virus software. Super Anti Spyware http://www.superantispyware.com Super Anti Spyware: ...

When trying to install Catalyst on Windows, I noticed some differences between Windows XP and Windows 7 64-bit installation of ActiveState perl. Namely, that dmake, and gcc would not install on the 64-bit version of Windows. Here are some of the problems I had. On Windows XP C:\Documents and Settings\scottm>cpan gcc.exe: Extraneous argument to `--' option gcc.exe: No input files specified. Set up gcc environment - It looks like you don't have a C compiler and make utility installed. Trying to install dmake and the MinGW gcc compiler using the Perl Package Manager. This may take a a few minutes... Downloading ActiveState Package Repository packlist...done Updating ActiveState Package Repository database...done Syncing site PPM database with .packlists...done Downloading MinGW-5.1.4.1...done Downloading dmake-4.11.20080107...done Unpacking MinGW-5.1.4.1...done Unpacking dmake-4.11.20080107...done Generating HTML for MinGW-5.1.4.1...done Generating HTML for dmake-4.11.200801...

Verify Network Connection Most people, who have been around redhat linux for a while, know how to check the IP address, and MAC address using ifconfig. Next, they would typically use route -n (or netstat -r) to find the gateway, and then ping it to verify a connection. Then maybe check duplex and speed using ethtool. Check the IP Address # ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:15:17:C1:54:D4 inet addr:10.10.5.67 Bcast:10.10.5.255 Mask:255.255.255.0 inet6 addr: fe80::215:17ff:fec1:54d4/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:342967 errors:0 dropped:0 overruns:0 frame:0 TX packets:353260 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:64963573 (61.9 MiB) TX bytes:262444897 (250.2 MiB) Memory:b8820000-b8840000 Discover the Gateway Address Then, it is common to check the default route with route -n, or netstat -nr. # route -n Kernel...