Author Archives: Robert
Error-Disable
When a network port encounters an error. This port is automatically shutdown to ensure network stability. When error-disable is enabled. The predefined error are as follows; arp-inspection bpduguard channel-misconfig dhcp-rate-limit gbic-invalid l2ptguard link-flap mac-limit link-monitor-failure loopback oam-remote-failure pagp-flap port-mode-failure psecure-violation … Continue reading
SSH error on cisco router
Enabling SSH on a Cisco router is not enough to guarantee SSH is working. Enabling ssh version 2.0 on a routers is as straight forward as;. >ip ssh version 1-2 I surely recommend the use of version 2, because ssh … Continue reading
DHCP Helper address
Which source ip address is used when relaying a dhcp-request ? Continue reading
GNS3 caveat – port status
Creating a network lab in GNS3 is reliefs on budget. But there are some drawbacks. One of which is port status. I have noticed that using GNS3 in combination with iouyap results in some unexpected behavior. Once a topology is made … Continue reading
Extended IP Access-list
As we all have learned in our pursuit to CCNA there are many different types of access-list. In reality most commonly used are ip access lists. Major difference between ip standaard access-list an ip extended access-list is the ability to … Continue reading
EIGRP neighbors
Cisco EIGRP protocol allows different methods to form neighborship relations. Default method is form neighborship automatically via multicast (multicast address of 224.0.0.10 is used) After an adjacency is formed ‘hellos’ are sent using IP protocol 88 (eigrp). This means that; … Continue reading
Cisco Express Forwarding
Differences between IP CEF , fast forwaring and processor based forwarding. Continue reading
Virtual Lab setup
Today I want to talk about the lab setup I have made. But first a slight warning; I will not discuss any use of illegal software nor will I tell you how to get IOS/IOU files. For quite some years … Continue reading
CCNP Books have arrived
The 300-115 (switch) book was already in my possession. This week the last two books arrived; 300-101 (route) and 300-135 (tshoot). For some time I was cramming labs from whichever tutorial I could lay my hands on. Now the study … Continue reading
T-Mobile – Evernote course
Last week I received an email with en invite to attend a free Evernote course. Free is good and Evernote is great tool to store and organize brainfarts. Immediately I jumped to the occasion to enroll to the course. I … Continue reading
