NETW206: A Survey On The Network's Health
Assessment on the Network’s Health
Name
DeVry University
NETW206: Introduction to Switching
Submitted to: NETW206
Professor:
Date: August 9, 2014
1. Describe in detail all issues associated with Layer 2 loops and VTP. Which switches in your recommended design should be STP roots for which VLANs? Which STP mode do you recommend? Justify your selection.
a. The issues associated with Layer 2 loops are many but can be deterred in order to not have to encounter said problems. For starters, Layer 2 should have the following topology in order to function and maintain high stability: Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and EtherChannel. The requirement to support STP convergence should be avoided by design. A Layer 2 loop happens when more than one layer 2 forwarding path exists between two given switches. The outcome: a switch receives a broadcast frame sends it to all of its trunk ports and access ports making an amplification for the broadcast of the loop which in turn creates an indefinite loop within the network. The way to prevent this was stated above which was to have; Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and EtherChannel. …show more content…
2.
Present best design practices to minimize Layer 2 loops and VTP.
a. This question was answer in my previous answer but the way to minimize Layer 2 loops is to have Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and
EtherChannel.
3.
This is what a Layer 2 loops looks like in a Spanning Tree loop on VLAN 10. The way to CONTROL and PREVENT this problem is to implement control plane policing. Control Plane Policing is a feature in Cisco routers and switches that enable administrators to configure QoS policies to protect the control plane against reconnaissance, denial-of-service (DoS) attacks, and other scenarios that can lead to exhaustion of CPU resources. Next, enable storm control. This feature is so there is no redundant information roaming around the network eating up excessive and unnecessary bandwidth. Lastly, have a PDU Hardware Rate Limit. This is a feature that enables Cisco routers to run at a significantly less amount of CPU than previously seen.
References
Johnson, A. (2014, May 19). Designing Cisco Enterprise Campus Architecture Models. > Designing High Availability in the Enterprise Campus. Retrieved August 7, 2014, from http://www.ciscopress.com/articles/article.asp?p=1315434&seqNum=2
Protecting a Cisco Catalyst 6500 Switch Against Layer 2 Loops. (n.d.). Protecting a Cisco Catalyst 6500 Switch Against Layer 2 Loops. Retrieved August 9, 2014, from http://www.netcraftsmen.net/resources/technical-articles/986-protecting-a-cisco-catalyst-6500-switch-against-layer-2-loops.html
Name
DeVry University
NETW206: Introduction to Switching
Submitted to: NETW206
Professor:
Date: August 9, 2014
1. Describe in detail all issues associated with Layer 2 loops and VTP. Which switches in your recommended design should be STP roots for which VLANs? Which STP mode do you recommend? Justify your selection.
a. The issues associated with Layer 2 loops are many but can be deterred in order to not have to encounter said problems. For starters, Layer 2 should have the following topology in order to function and maintain high stability: Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and EtherChannel. The requirement to support STP convergence should be avoided by design. A Layer 2 loop happens when more than one layer 2 forwarding path exists between two given switches. The outcome: a switch receives a broadcast frame sends it to all of its trunk ports and access ports making an amplification for the broadcast of the loop which in turn creates an indefinite loop within the network. The way to prevent this was stated above which was to have; Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and EtherChannel. …show more content…
2.
Present best design practices to minimize Layer 2 loops and VTP.
a. This question was answer in my previous answer but the way to minimize Layer 2 loops is to have Spanning Tree Protocol (STP), Trunking (ISL/802.1q), Unidirectional Link Detection (UDLD), and
EtherChannel.
3.
This is what a Layer 2 loops looks like in a Spanning Tree loop on VLAN 10. The way to CONTROL and PREVENT this problem is to implement control plane policing. Control Plane Policing is a feature in Cisco routers and switches that enable administrators to configure QoS policies to protect the control plane against reconnaissance, denial-of-service (DoS) attacks, and other scenarios that can lead to exhaustion of CPU resources. Next, enable storm control. This feature is so there is no redundant information roaming around the network eating up excessive and unnecessary bandwidth. Lastly, have a PDU Hardware Rate Limit. This is a feature that enables Cisco routers to run at a significantly less amount of CPU than previously seen.
References
Johnson, A. (2014, May 19). Designing Cisco Enterprise Campus Architecture Models. > Designing High Availability in the Enterprise Campus. Retrieved August 7, 2014, from http://www.ciscopress.com/articles/article.asp?p=1315434&seqNum=2
Protecting a Cisco Catalyst 6500 Switch Against Layer 2 Loops. (n.d.). Protecting a Cisco Catalyst 6500 Switch Against Layer 2 Loops. Retrieved August 9, 2014, from http://www.netcraftsmen.net/resources/technical-articles/986-protecting-a-cisco-catalyst-6500-switch-against-layer-2-loops.html