RIPv2, isn’t that hard at all.
There are a few enhancements from RIPv1:
- Authentication: clear text (by default) or MD5
- Subnet masks: RIPv2 is classless
- Next-Hop IP address: to avoid routing loops (used in networks with multiple routing protocols)
- Updates are send by multicast, to IP 126.96.36.199
Frame-Relay Traffic Shaping (FRTS) can be hard to understand.
Traffic shaping vs policing
The most important difference between these two is the fact that shaping is designed to delay excess traffic, whereas policing drops the excess traffic.
Shaping uses credits. Before a packet can be sent, the amount of credits equaling the packet size in bits have to be available. Policing is not designed to guarantee bandwidth, it’s designed to limit bandwidth.
Private VLAN configuration could be tricky:
A Private VLAN environment consist of a few VLANs:
- Primary VLAN
- Secondary VLAN
- Community VLAN
- Isolated VLAN
Every Secondary VLAN will be associated to a primary VLAN. Every primary VLAN can exist of multiple community VLANs but only 1 isolated VLAN.
When a broadcast storm occurs, even with STP enabled, there is another option to protect your network from broadcast flooding. This method is called storm-control. The technics of this protocol are simple:
Stom control configuration is based on a per-port bases and storm control can be enabled for broadcasts, unicasts and/or multicasts. When configuring stormcontrol, you have to specify the rising and falling values: the rising value is the value on which an action should occur (rate-limit the traffic to this value, err-disable this port or send a SNMP trap). The rising value is the value on which the action will be undone.
This is another (short) post about three more important features of spanning-tree, as discussed on my previous blog.
Spanning-tree root guard is useful in avoiding layer 2 loops during network anomalies. Root guard forces an interface to become a designated port to prevent switches from becoming a root switch.
My first day of study: it’s a spanning-tree day! Most of the information is a fresh-up from the CCNP course, but still very usefull to know. Below a summary of some key-parts of spanning-tree, rapid-spanning-tree and mst.
Spanning-tree bridge ID format
The “old” version of spanning-tree, also known as 802.1d, uses the following bridge ID format:
The priority is a 2 bytes (16 bits) field with all possible values between 0 and 65535. The MAC address is used as a tiebraker.
This is my first blog on this new blog site. I’ m quite happy with the looks and feels of this WordPress installation: it’s so easy to start and I realized that I should have been started a blog ages ago…
This new year, 2011, is just a few days old and I’ve decided to begin a ‘new’ study course: CCIE Routing & Switching. There is a lot of information about this topic on the internet: other blogs, mail groups, news groups, but I would like to share all study-related topics I’m going to experience in the upcoming months.