Section 2.1.b (i) UDLD Unidirectional Link Detection is a Cisco Proprietary protocol used to detect issues with links that utilize separate cables (fiber). UDLD can be enabled and becomes active when it detects a neighbor from the other side (both sides must be configured) Thus UDLD can only successfully work when configured on both …
2.1.b (i) CDP, LLDP
Section 2.1.b (i) CDP, LLDP CDP: We will start this discussion with the Cisco Discovery Protocol (CDP), a proprietary protocol invented by Cisco for finding directly connected device information. CDP is encapsulated in 802.3 Ethernet not Ethernet II. This feature is enabled by default and transmits every 60 seconds with a hold/expire time of …
2.1.b Implement and Troubleshoot Layer 2 Protocols
Section 2.1.b Implement and Troubleshoot Layer 2 Protocols One thing I wanted to discuss in this section is Ethernet, and all of the forms it may take. When looking at wireshark captures, we may notice the Ethernet headers as “Ethernet II”. This is the most common Ethernet protocol we use today. The above screenshot …
Continue reading "2.1.b Implement and Troubleshoot Layer 2 Protocols"
1.1.f (i) Starvation
1.1.f (i) Starvation This section discusses TCP Starvation, UDP dominance. As you now know, TCP is connection oriented, and is able to detect network congestion and act accordingly (slow start following by back off with packetloss). UDP has no concept of this congestion window, all UDP will do is continue to send whatever the upper …
1.1.f Flash Cards
Here are all of the flash cards for 1.1.f Explain UDP Operations ! If you don’t have or know what Anki is, it is my favorite , free flash card program: https://apps.ankiweb.net/ Here is the Anki package you may import and start using the flash cards right away: https://upw.io/u9/1.1.f_Explain_UDP_Operations.apkg If you prefer the plain text …
1.1.f (ii) Latency
1.1.f (ii) Latency In UDP we have less data protocol latency as compared to TCP. TCP would have to ack and even set up a connection before sending. In UDP we just start sending. However it is important to note that UDP applications themselves are more latency prone. The choice of UDP means the …