My CISCO Journal

NTP : Network Time Protocol Services on CISCO routers. Time synchronization is very critical on CISCO routers, as without accurate date and time settings, we would not be able to generate any meaningful logs on the routers. Most of the time, all the devices on a network are...

G.711 has a Mean Opinion Score of 4.3-4.7 and uses 80 kpbs (if you send 50 packets/second with 20 ms of RTP payload per packet) or 74.7 kbps (@ 30 ms, meaning 33.3 packets/second). G.729 (NOT G.729a) has a MOS of 3.9-4.2 and uses 24 kbps @ 20 ms or 18.7 kbps @ 30 ms. G.729a has a MOS of 3.7-4.2 and uses 24 kbps @ 20 ms or 18.7 kbps @ 30 ms. G.723...

VRRP: Virtual Router Redundancy protocol To reach remote networks we use the following methods to discover the first hop to our remote network: Dynamic process Static configurations The problem with dynamic exploration is extra network overhead, and usually static...

One of the many services that we mostly need in our network is DHCP. The Dynamic Host Configuration Protocol is used to dynamically assigned IP addresses and Default gateway information to the host on a network. In simple words, the DHCP functionality can be expressed as: As...

PART II: Suppose our ISP owns an address block: 200.24.0.0/16. What this means? An address block comprises of different address that the ISP can allocate and sell to its customers. The IP address block 200.24.0.0/16 can represent 2^16 = 65, 536 IP addresses. Suppose from this block it wants to allocate 200.24.15.0/20 address block. So how...

PART I: CIDR (RFC: 4632): Classless inter domain routing. In simple words, CIDR is like supernetting route summarization and VLSM at the ISP end that’s why it is called Classless inter domain routing. Confusing? Okay let us discuss it via an example; it will help us picture the whole concept. As we learned in route summarization, instead of...

GLBP Configurations: We will use GNS3 to implement GLBP. We are using two hosts with same default gateway. Our configuration check list is: Basic GLBP Configuration GLBP priority and preempt GLBP MD5 authentication GLBP Load Balancing Method AVG and AVF Failover GLBP Packet...