Saturday, May 26, 2007

Subletting and Network assessment for Small Office






Here is another situation. We are hired as a network consultant to SMTP25.org. This company has point to point network connection as it is illustrated in the Visio diagram. Clients are complaining about not being able to open their files from their workstation. Client is using roaming profile, even though they don't travel except 100 remote users. Exchange is very slow and users get kicked out from exchange frequently every day. Come up with a good plan and don't worry about the budget. Tell me what is wrong with existing network, and tell me how you are going to fix the existing issues

Network A

  • What is Network IP address
  • What is Default Gateway IP address
  • First usable IP address
  • Last usable IP address
  • Broadcast IP address
  • Create DHCP Scope
  • Reserve IP addresses for server ( how many servers)
  • How many Exchange servers?
  • How many DC?

Network B

  • What is Network IP address
  • What is Default Gateway IP address
  • First usable IP address
  • Last usable IP address
  • Broadcast IP address
  • Create DHCP Scope
  • Reserve IP addresses for server ( how many servers)
  • How many Exchange servers?
  • How many DC?

Network C

  • What is Network IP address
  • What is Default Gateway IP address
  • First usable IP address
  • Last usable IP address
  • Broadcast IP address
  • Create DHCP Scope
  • Reserve IP addresses for server ( how many servers)
  • How many Exchange servers?
  • How many DC?


Existing

Total users: 1200

Network A = 300 users

Network B = 500 users

Network C= 300 user

Remote users =100 users


The given host IP Address is 151.123.12.0 /20, by location this host in one of the networks, will lead you to get all the IP addresses for all the networks

Users are complaining network is very slow. The company has two servers one DC and one exchange server. The DC is DNS, DHCP, FUSMO roles (all) Exchange is, file server, backup server, antivirus server. Design the best network for SMTP25 Company. Make users happy. Think about the server performance. Come up with a plan and tell me how many server do I need and where I should place them? I need a complete network setup from ground. I need you guys design exchange infrastructure, tell me which version of exchange I need here in this company. Make the design as simple as it can be and think about a future growth. Finally subnet this network pleases and assigns IP addresses for each server, DHCP scope and so forth

Thanks everyone for their contributions

Best regards

Oz ozugurlu

3 comments:

Rod said...

In the above problem, if CIDR = 240, it wont be able to support 500 users. It wont even support 20 users. I think there is a typo. Please double check on it again. Thanks.

Oz Ozugurlu said...

Rod, SM is /20, plenty of room for Networks as well as hosts in each networks

Best
oz

Rod said...

Given: 151.123.12.0 /20

Solution:

Subnet mask = 255.255.240.0
Total Networks = 16
Hosts in ea.Network = 4094

Calculations:
For subnet mask:
20 bits on out of 32 bits. Therefore we have 12 bits left.
4 bits for networks.
12 bits for hosts.
smallest increment = 16

For determining total networks:
2^N where N= exponential power

2 raised to the 4th power = 16

For hosts per networks:
2^N - 2

2^12 - 2 = 4096 - 2
= 4094

16 networks are:

151.123.12.0 / 20
151.123.12.16 / 20
151.123.12.32 / 20
151.123.12.48 / 20
151.123.12.64 / 20
151.123.12.80 / 20
151.123.12.96 / 20 ( 7th network )
151.123.12.112 / 20
151.123.12.128 / 20 ( 9th network )
151.123.12.144 / 20
151.123.12.160 / 20
151.123.12.176 / 20
151.123.12.192 / 20
151.123.12.208 / 20
151.123.12.224 / 20
151.123.12.240 / 20

Network A :

Network IP address = 151.123.12.0
Default gateway = 151.123.12.1
Broadcast IP address = 151.123.12.15
1st usable IP address = 151.123.12.2
Last usable IP address = 151.123.12.14
DHCP scope:
151.123.12.2 to 151.123.12.14
Reserved IP address
( 5 hosts/network):
151.123.12.2 to 151.123.12.6

Network B ( 9th network )

Network IP address = 151.123.12.128
Default gateway = 151.123.12.129
Broadcast IP address = 151.123.12.143
1st usable IP address = 151.123.12.130
Last usable IP address = 151.123.12.142
DHCP scope:
151.123.12.130 to 151.123.12.142
Reserved IP address
( 5 hosts/network):
151.123.12.130 to 151.123.12.134

Network C ( 7th network ):

Network IP address = 151.123.12.96
Default gateway = 151.123.12.97
Broadcast IP address = 151.123.12.111
1st usable IP address = 151.123.12.98
Last usable IP address = 151.123.12.110
DHCP scope:
151.123.12.98 to 151.123.12.110
Reserved IP address
( 5 hosts/network):
151.123.12.98 to 151.123.12.102