A BGP router considers each neighbor to be either an internal BGP (iBGP) peer or an external BGP (eBGP) peer. Each BGP router resides in a single AS, so neighbor relationships are either with other routers in the same AS (iBGP neighbors) or with routers in other autonomous systems (eBGP neighbors). The two types of neighbors differ only slightly in regard to forming neighbor relationships, with more significant differences in how the type of neighbor (iBGP or eBGP) impacts th..
EIGRP uses a sophisticated metric that considers bandwidth, load, reliability, and delay. That metric is Although this equation looks intimidating, a little work will help you understand the math and the impact the metric has on route selection. You first need to understand that EIGRP selects path based on the fastest path. To do that it uses K-values to balance bandwidth and delay. The K-values are constants that are used to adjust the relative contribution of t..
Multilink PPP, abbreviated as MLP, MP, or MLPPP, defines a method to combine multiple parallel serial links at Layer 2. The original motivation for MLP was to combine multiple ISDN B-channels without requiring any Layer 3 load balancing; however, MLP can be used to load balance traffic across any type of point-to-point serial link. MLP balances traffic by fragmenting each packet based on the number of parallel links and then sending one fragment over each link. For each pack..
Overview of Communications History
Networks are now a core component of our business and personal lives. Today, businesses that may hobble along with the loss of telephone service can be rendered nonfunctional by the loss of their data network infrastructure. Understandably, corporations spend a great deal of time and money nursing this critical resource. How and why did this dependency occur? Simply because networks provide a means to amplify all the historical communication mechanisms. Nearly 50,000 ye..
Multilayer switching began as a dual effort between a route processor (RP) and a switching engine (SE). The basic idea is to “route once and switch many.” The RP receives the first packet of a new traffic flow between two hosts, as usual. A routing decision is made, and the packet is forwarded toward the destination. To participate in multilayer switching, the SE must know the identity of each RP. The SE then can listen in to the first packet going to the router and also..
