There is Cisco router of 7200 series with 4 FastEthernet interfaces (FE) and 2 serial ports. It should act as load balancer and failover for LAN connected to it via one FE 1/0 interface while two identical Internet connections are going to FE 0/0 and… Read More »Cisco Load Balancing with Failover setup example
Using nfsen it is possible to view IP traffic statistics on Linux interfaces including the graphs showing data sent and received (see the screenshot to the right) as well as historical information about all data transfers. So after you’ve configured nfsen and nfdump to monitor… Read More »Install nfdump and nfsen netflow tools in Linux
It was long time ago when I wrote here last time but today I’d like to share the link to an application that would be appreciated by everyone starting from Linux starter wishing to speed up his/her Internet connection and ending with system administrators who… Read More »Namebench: cross-platform DNS benchmarking tool
By default Cisco IOS doesn’t provide any traffic monitoring tools like iftop or iptraff available in Linux. While there are lots of proprietary solutions for this purpose including Cisco Netflow Collection, you are free to choose nfdump and nfsen open source software to monitor traffic… Read More »How to monitor traffic at Cisco router using Linux (Netflow)
Preparing for Cisco certification exam and need real equipment required to accomplish all those CCNA or CCNP labs? That’s not a problem any more. This is due to availability of Packet Tracer for Linux and Community Lab hosted by people behind packetlife.net. As for Packet… Read More »Access to real Cisco routers and switches for free
Hosts from LAN1 should be able to access hosts at LAN2 and vice-versa through GRE tunnel between R1 and R2. ISP doesn’t care what networks are behind R1 and R2 so the only way to establish connection between LAN1 and LAN2 is to use VPN, in this example we use GRE.
Today Google unveiled its new project: Google Public DNS. It means now anybody can use Google’s DNS managed servers for resolving domain names into IP addresses and back. According to Google it should speedup browsing as well as security. Hope I won’t see adsense ads once tried to load expired domain name (that’s how OpenDNS acts today).
Here are easy-to-remember Google Public DNS IP addresses: 188.8.131.52 and 184.108.40.206.
Below is the link list to essential Cisco related cheat sheets (collection of notes or quick reference guides whatever). By the way, we don’t recommend to cheat anything and/or do a cheating of any sort by means of using these materials 😉 1. Cisco IOS… Read More »15+ “must have” Cisco Cheat Sheets
$GENERATE directive is available in multi platform DNS server BIND since 8.2 version. It helps you to create hundreds or thousands of resource records with one line in zone file.
Nice example is to use $GENERATE in order to make PTR records for certain DNS zone.
ipcad is IP accounting daemon with Cisco-like ip accounting export. It runs in background, listens traffic on the specified interfaces, and records the traffic for later retrieval and analysis. Here is a piece of shell code that allows to export ipcad output into sqlite3 database… Read More »Dump ipcad output into sqlite3