OPS535 Notes

Day 4

learn name: rchan

account on matrix: /home/rchan

file system: the root (the starting point) is /

dns system: the root (the starting point ) is . (dot)

what is the minimum of partition(s) do you need to install Linux?

(a) 1 - 1 (v) - root file system (b) 4 - 4 (c) 2 - 2 (d) 3 - 4

. domain - root domain - root name server

note: All caching only DNS servers must know who are the root name servers (i.e. their IP addresses)

scs.senecac.on.ca

Caching name server will ask one of the 13 root name server the question: what is the IP address for scs.senecac.on.ca

Answer back from the root name server: Sorry! I don't know, but you can ask the name server for the "ca" domain, And here is its name (xxxxx) and ip address (ddddd)

....

Caching name server will ask one of the Name server for the senecac.on.ca domainthe question: what is the ip address for scs.senecac.on.ca

possible answers: (1) There is no such host.

                 (2) the ip for that host is 142.240.140.179

What will be the TTL for the cached records in the caching name server.

(a) 7 days (b) forever (c) 15 minutes (d) depends on where is coming from (v)

What if it is coming from the name server for senecac.on.ca?

(a) Let take look or talk to the DNS administrator of senecac.on.ca domain (b) it depends on what kinds of DNS records

Is there a field in each DNS record that we can specify the TTL? yes. there is a global field and a local field for each record in the zone file

Why do we need such kind of information? So that the authoritative DNS server for the DNS record is still in control of the DNS mappings.

Does your primary name server nedd the information about the 13 root name servers?

Yes/no and why? No, no, no. if you don't want your primary name server to keep any DNS cache!