Questions and Answers about Cisco 3850 Switches

 Today I am going to talk about the queries about the Cisco 3850 Switch as it is one of the most used switch at the access layer in the large enterprise network and at core layer in some of the small and the mod sized enterprise networks. 

I will address some of the concerns which some of you have for using the Cisco 3850 switch in your network. Below are some of the questions and the answer to that questions regarding the Cisco 3850 switches.

Fig 1.1- Cisco 3850 Switch

Q: What are the supporting uplink modules in the Cisco 3850 Switches ?
A: There are some of the supported uplink network modules in Cisco 3850 Switches and these are 

  • 4x 1G Network Module 
  • 2 x 1/10 G Network Module
  • 4 x 1/10 G Network Module and can be used for 48 port RJ models
  • 8 x 10 G Network Module
  • 2 x 40 G Network Module
Q: Does the Cisco Catalyst 3850 10G SFP+ 48-port switch support uplink modules ?
A: No. It has 4 fixed 40G QSFP ports for uplinks. 

Q: Are the uplinks between the Cisco Catalyst 3850 and the 3750-X interchangeable?
A: No Because they are not compatible with each other.

Q: How do you manage the Cisco Catalyst 3850 ?
A: Cisco Catalyst 3850 can be managed using the Cisco IOS Software CLI or using Cisco Prime 

Q: What is the maximum number of VRFs that can be configured on a Cisco Catalyst 3850 ?
A: 27

Q: Does the switch support auto-baud on the console port?
A: No

Q: What type of airflow do the Cisco Catalyst 3850 switches support ?
A: Cisco Catalyst 3850 is “front and sides” to back airflow except for the 48-port 10G SFP+ switch. The 48-port 10G SFP+ switch has support for front-to-back and back-to-front airflow. 

Q: What are the power consumptions for copper and fiber SKUs ?
A: For 24 port copper SKU the power consumption is 200W and for 48 port its 280W. In the case of both 12 Port and 24 Port fiber SKUs its 200W. 

Q: Can the Cisco Catalyst 3850 act as a wired switch ?
A: Cisco 3850 is a wired switch as well as a converged wired wireless switch.

Q: What about service modules for the Cisco Catalyst 3850 ?
A: There are no service modules for the Cisco Catalyst 3850 

Q: Is there an onboard web GUI on the Cisco Catalyst 3850 ?
A: Yes

Q: Can both console ports in Cisco 3850 Switch be used simultaneously ?
A: No. When the USB console is used, the RJ-45 console receives the output of the USB console as well.

Q: What is an RTU licensing model ?
A: RTU is a trust-based licensing model designed to give customers the flexibility to upgrade, downgrade, or move the license for RMA purpose by using simple EXEC CLI commands 

Q: Do the Cisco Catalyst 3850 switches require a product activation key (PAK) for licensing ?
A: No PAK is required for software licensing in Cisco Catalyst 3850 switches. 

Q: What are the different types of licenses in the Cisco Catalyst 3850 ?
A: There are two main types of Cisco Catalyst 3850 license: permanent RTU license and evaluation RTU license.

Q: How is the license information stored and protected ?
A: The license information is stored in two hidden flash partitions: Active and Backup. They are not customer accessible, and write erase will not erase the license files. If the license file in the primary partition is corrupted or tampered with, the license file from secondary/backup partition is used. If both the partitions are corrupted, Cisco will recreate the license files. 

Q: How is stacking done in the Cisco Catalyst 3850 ?
A: Cisco Catalyst 3850 introduces a revolutionary stacking technology called Cisco StackWise-480. It offers a stacking bandwidth of 480 Gbps nonblocking, and it supports Cisco IOS Software Stateful Switchover (SSO) technology. Both the stacking cables and connectors have been revamped in the Cisco Catalyst 3850 for easy installation and removal. 

Q: What is SSO technology?
A: Cisco SSO technology synchronizes the Layer 2/3 and wireless tunnel protocol state machines from Active to Standby stack switch. During Active switch switchover the Standby switch performs graceful-recovery with neighbours without disrupting network topology. 

Q: What is Nonstop Forwarding (NSF) technology?
A: The complementary NSF technology enables business continuity by delivering nonstop forwarding communication, while the Standby switch is transitioning in the Active role. 

Q: How does new Cisco IOS XE Software change the Cisco Catalyst 3850 stack architecture ?
A: The next-generation Cisco Catalyst 3850 becomes modularized and fully distributed with a highly resilient stackable system with the next-generation Cisco IOS XE Software architecture. 

Q: Is there a way to know the power-shedding priority of my stack ?
A: Yes. A CLI is available to display the current set of priorities for the entire stack. See the command reference for “show stackpower.” 

I will come up with more questions in part -2 to explain features of Cisco 3850 Switch. Please share your questions as well so that i can address the same.