Generate a CSR for WLC webauthentication Last week i was instructed to prepare our Wireless LAN Controller to work with the webauth 3rd party unchained certificate for external visitors. We want to provide a certain security feeling for the customers, if they combine with us about wlan access. Background Information By default, WLCs use a built-in self-signed SSL certificate. The WL

It is useful to get familiar with the ‘sh int counters’ command, to check if the switchport/interface (switchport-interface) generate failure on the physical or data link layer. In some cases clients has latencies or packet loss and therefore bad network performance. In this blog i want to explain to perform the right outputs and contrue for the troubleshooing. This will

To clear a vty line (telnet/ssh) connection on a cisco device you have to know, how to interpret the ‘sh line’ output. To show the line output you can choose the following line-commands. With the ‘sh whoami’ command you can see on which vty line you are connected. I’ am connected on Line 2. With the ‘sh users’ command you see, that i was con

singlemode / multimode fiber Here you can the see the composition of a fiber cable multimode 50µm / multimode 62.5µm / singlemode 9µm fiber categories and areas of operation category color code fiber type attenuation in dB/km minimal modal bandwidth OFL in MHz•km EMB2 in MHz•km 850 nm 1310 nm 1383 nm 1550 nm 850 nm 1310 nm multimode fiber OM1 Orange G62,5/125 3,5 1,5 n.a. n.a. 200 5

I will show a little tricky thing about Layer 3 communication between different vlans. Given the following figure.   So it is a very silly thing. On SW1 you have configured vlan30 for port fa0/1 and fa0/2. On Switch SW2 you have configured Vlan20 for port fa0/3 and fa0/1. Configuration With this configuration PC1 can ping PC2 vice versa. The only logging entry you get is as fol

Cisco NTP basics NTP is a protocol designed to synchronize clock with a atomic- or a radio clock. The NTP Protocol uses the current standard of protocol version 4. NTP is reserved for the UDP-Port 123. The timestamp at NTP are 64bit long. 32 bits encode the seconds since the beginning of 1. Januar 1900 00:00:00. The next 32 bits are the fraction of the seconds. With this manner it i