Sw1
Config t
Archive
Log config
Logging enable
Notify syslog
R1
Config t
Ip flow-top-talkers
Match source address 172.16.2.1/30
Int et0/2
Ip flow ingress
Copy run start

The script defines a dictionary of VLANs with their associated IP addresses and then prints each key-value pair from this dictionary. In Python, when you iterate over a dictionary using the .keys() method and print both key and value, it will be displayed as tuple type because it's printing two immutable elements together.

Explanation

Explanation
The stratum levels define the distance from the reference clock. A
reference clock is a stratum 0 device that is assumed to be accurate and has little or no delay associated with it. Stratum 0 servers cannot be used on the network but they are directly connected to computers which then operate as stratum-1 servers. A stratum 1 time server acts as a primary network time standard.

A stratum 2 server is connected to the stratum 1 server; then a stratum 3 server is connected to the stratum 2 server and so on. A stratum 2 server gets its time via NTP packet requests from a stratum 1 server. A stratum 3 server gets its time via NTP packet requests from a stratum-2 server... A stratum server may also peer with other stratum servers at the same level to provide more stable and robust time for all devices in the peer group (for example a stratum 2 server can peer with other stratum 2 servers).
NTP uses the concept of a stratum to describe how many NTP hops away a
machine is from an authoritative time source. A stratum 1 time server
typically has an authoritative time source (such as a radio or atomic clock, or a Global Positioning System (GPS) time source) directly attached, a stratum 2 time server receives its time via NTP from a stratum 1 time server, and so on.
Reference: https://www.cisco.com/c/en/us/td/docs/routers/asr920/con
figuration/guide/bsm/16-6-1/b-bsm-xe-16-6-1-asr920/bsm-timecalendar-
set.html