why do you want to leave your current role ?why are you want to apply for this position?
what is your troubleshooting process ?
what do you like mostly about the current role ?
what is your daily route ?
how big is your team ?
what is DNS ? what is DHCP ? DHCP message ? different between TCP and UDP ?
Just a general questions + some basic technical (what is TCP, UDP, DNS, DHCP).
you need to know the in and out of DHCP, STP, ARP, basic routing, port security and troubleshooting. Basics basics basics.... that is the only requirement.
Each interview went through a networking scenario where something(s) was causing an issue with the network and you had to work through things to find and resolve it. Need to know: how ARP works, DHCP, basic packet contents, DNS, ACL, subnets, among others.
DHCP DORA process in detais including packet contents.
DORA process packet contents? source &destination add. in each packets?
is a network management protocol used on TCP/IP networks whereby a DHCP server dynamically assigns an IP address
and other network configuration parameters to each device on a network so they can communicate with other IP networks.
- The DHCP client broadcasts a DHCPDISCOVER message on the network subnet using the destination address 255.255.255.255
When a DHCP server receives a DHCPDISCOVER message from a client, which is an IP address lease request, the DHCP server reserves an IP address for the client and makes a lease offer by sending a DHCPOFFER message to the client. This message contains the client's MAC address, the IP address that the server is offering, the subnet mask, the lease duration, and the IP address of the DHCP server making the offer.
In response to the DHCP offer, the client replies with a DHCPREQUEST message, broadcast to the server,requesting the offered address. A client can receive DHCP offers from multiple servers, but it will accept only one DHCP offer.
sending a DHCPACK packet to the client. This packet includes the lease duration and any other configuration information that the client might have requested. At this point, the IP configuration process is completed.
Difference between ARP and CAM table.
ARP table resolves IP address to Mac Address, is used to maintain a correlation between each MAC address and its corresponding IP address.
CAM table, is present in all Cisco Catalysts for layer 2 switching. It is used to record a stations mac address and it's corresponding switch port location.
What information is carried by BPDU packets:
exchange information about bridge IDs and root path costs.
There are two types of BPDUs in the original STP ):
- Configuration BPDU (CBPDU), used for Spanning Tree computation
- Topology Change Notification (TCN) BPDU, used to announce changes in the network topology
1st round was scheduled, which was around 1/2 hour asked to explain DHCP, DNS, tcp vs udp
also why cisco Meraki and what it does.
DHCP ? Working ? DORA - what types of messages are sent on each step ? (broadcast/unicast/multicast)
What is... ARP/OSPF etc...
The address resolution protocol,to map IP network addresses to the hardware addresses.
What is STP? Describe it's packet interactions.
What is DHCP? Describe it's role and operation in the provided network diagram.
What is DNS? What is it's purpose? Describe it's operation.
domain name system , used to resolve human-readable hostnames into machine-readable IP
The first place your computer looks is its local DNS cache, which stores information that your computer has recently retrieved.
our computer queries (contacts) your ISP’s recursive DNS servers
If the recursive servers don’t have the answer, they query the root name servers
The root nameservers will look at the first part of our request, reading from right to left —www.dyn.com — and direct our query to the Top-Level Domain (TLD) nameservers for .com
Ask the authoritative DNS servers
The TLD nameservers review the next part of our request —www.dyn.com— and direct our query to the nameservers responsible for this_specific_domain. Theseauthoritative nameserversare responsible for knowing all the information about a specific domain, which are stored inDNS records.
Retrieve the record
The recursive server retrieves the A record for_dyn.com_from the authoritative nameservers and stores the record in its local cache.
Receive the answer
Armed with the answer, recursive server returns the A record back to your computer.
What is TCP? Describe a typical packet exchange. What is the difference between TCP and UDP? What protocols would use one or the other?
TCP (Transmission Control Protocol ) is a standard that defines how to establish and maintain a network conversation via which
application programspacket can exchange data. TCP works with the Internet Protocol , which defines how computers send datas of to each other.
Describe the OSI model.
TheOSI reference model describes how data is sent and received over a network. This model breaks down data transmission over a series of seven layers.
What is a routing protocol? What is the difference between link-state and distance vector?
Distance vector:
uses Hops to find its way good for small networks simple to implement slower to converge
Link State:
updates are triggered by an event reeks havoc on the processor
uses "hellos" to connect to its neighbors
faster to converge
What is a VLAN? What types of VLANs are there and what are their properties?
partitions the network into logical segments, which provides better administration, security, and management of multicast traffic.
Default VLAN: This is basically where ALL ports belongs to by default, this is tecnically VLAN 1 and it can't be deleted from the switch. On some (old )Catalyst switches you can't even disallow VLAN 1 from trunk ports.
Data VLAN: This is the "normal" VLAN where the traffic is carried and where the client data goes through the LAN.
Native VLAN: The native VLAN is an 802.1Q only concept. Traffic belonging to the native VLAN is not tagged. Note that by default VLAN 1 (which is the default VLAN) is the native VLAN on ALL Catalyst switches. You can designate any VLAN as your native on your switch and note that it need to match on both ends of the trunk connection.
Voice VLAN: The voice VLAN is where the QoS policies are applied in order to prioritize this traffic to send it through the LAN. The voice traffic it's always distinguished from the data traffic on the LAN.
Management VLAN: This is used on a LAN for management purporses. Example of this would be to use it on a Out-of-Band (OOB) implementations. This VLAN normally carries sensitive traffic from a control perspective; some of the protocols that are carried on this VLAN are: FTP, TFTP, Telnet, SSH, SCP, and others.
Special VLANs: These VLANs are basically used for special cases on your LAN. An example of a special case VLAN would be VLAN 0, which is used in conjunction with 802.1p. I would say that VLAN 1 fits in this "special" category too.
Reserved VLANs: There are some VLANs that are reserved internally on your switch in order to use them on other enviroments like FDDI, Token Ring. The specific VLANs used for these two types of networks are from 1002 - 1005.
Private VLANs it's a technology that has some new concpets/category of VLANs, but these are not a CCNA R&S related topic
What are two types of ports for VLANs? How are they different?
What frequencies are used by wireless devices? How many channels per frequency? Describe a wireless protocol of your choice.
What is the difference between client VPN and site-to-site VPN?
What is IPsec? Describe it's operation.
Internet Protocol Security is a set of protocols which sit on top of the Internet Protocol ( IP ) layer. It allows two or more hosts to communicate in a secure manner by authenticating and encrypting each IP packet of a communication session.
Can explain how the OSI Model works?
How does a router work at Layer 3?
How do switchers communicate at Layer 2? Since they use MAC addresses.
why networking
because I have the passion about it , this first time I meet network , I was addicted to the different protocols ,dealing with network to make it better ,you can contribute to ensure that people can connect to each other or access to the information they need more smoothly which is very meaningful.and I also like to troubleshoot the network issues which keeps me satisfied.
why cisco meraki（this position）
As I know,you have comprehensive set of solutions includes wireless, switching, security, communications which makes the networking easier , faster and smarter, this is exact the original intention why I want to do network. your open floor environment allows engineers to brainstorm ideas with others who are just as passionate about networking and solving problems which is very cool .I believe I can use I have learnt to not only achieve my value but also can make a contribution to the company . Meraki has grown to become an industry leader in the IT space, with over millions network devices and counting online around the world.it would be honered to work in a company as you.