Category Archives: Cisco Networking

For courses, entertainment and educational purposes.

The Spanning Tree (SPT) Algorithm explained in detail

Posted on 7 May 2012 by pim

Spanning Tree Protocol SPT Note: The phrase “bridge” can be read as switch as well in the explanantion below. 1. Elect the Bridge with the LOWEST Bridge – ID (BID = Priority. MAC) as root bridge. The default Priority is … Continue reading →

Posted in Cisco Networking | Leave a comment

How to recover a Cisco 2600 router and restore IOS

Posted on 18 April 2012 by pim

Boot in Rommon by interupting the boot of the router via a SEND BREAK on the Serial Console during the boot. rommon 13 > TFTP_FILE=c2600-adventerprisek9-mz.124-16.bin rommon 14 > IP_ADDRESS=10.1.1.3

Posted in Cisco Networking | Leave a comment

To create an etherchannel (“aggregation”) with IEEE 802.1q trunking on Solaris 10

Posted on 18 April 2012 by pim

1. Create the Etherchannel and bring it up: laks:/root # dladm show-dev nge0            link: up        speed: 100   Mbps       duplex: full rge0            link: up        speed: 100   Mbps       duplex: full rtls0           link: unknown   speed: 100   Mbps       duplex: unknown

Posted in Cisco Networking, Technical | Leave a comment

To configure a freeradius server for a cisco switch

Posted on 18 April 2012 by pim

0. As of recent, starting the free radius daemon on eg Debian like OS-es might provide you with hassle regarding permissions on the SSL keys. In case of startup problems, start the daemon with “-X” or run “strace -t open” … Continue reading →

Posted in Cisco Networking, Technical | Leave a comment

Subnetting example(s) and manual route summarization

Posted on 18 April 2012 by pim

1. A network administrator has been provided with the following Class B block of IP addresses: 172.16.0.0/16 It is his task to subnet this Classful network to have (at least) 9 subnets available and maximize the number of hosts available … Continue reading →

Posted in Cisco Networking, Technical | Leave a comment

To setup a Cisco router as TFTP server

Posted on 18 April 2012 by pim

On the router to be server: RouterA(config)#tftp-server flash:c2800nm-advipservicesk9-mz.124-16.bin NO / after flash: !

Posted in Cisco Networking, Technical | Leave a comment