Question

1. ACLs allow a router to control traffic within a network. The concept is very similar to how firewalls operate. Would a router configured with ACLs be a plausible replacement for a true perimeter firewall product such as a Cisco ASA or a SonicWall? Why or why not?

2. What’s the advantage of using a journaling file system over non-journaling? Under what circumstances might you use a non-journaling file system? Give examples of each type.

3. RAID is used in nearly all enterprise storage environments. What are some of the advantages to using RAID? When would one RAID level be used over another?

4. Extended ACLs allow for a great deal more granularity than do Standard ACLs. Give examples of circumstances when you would use either.

Answer 1

1. I think a firewall is configured to perform a lot of functions with high optimizations than a router can perform.

For eg. A true firewall allows you to limit the commands available to a FTP client and also it can handle upto layer 7 controls. Also it has higher capacity for handling VPN traffic connections. Moreover, ACL's dont have the feature of stateful packet inspection or intrusion detection. They can only allow or deny a packet

2. Key ideas:

• we use journaling file system when we have multiple users working on the same data and we need to maintain consistency.
• When we have storage space for metadata, we tend to use journaling file system.
• if there is high probabiity of crash, we can use journaling file system for conserving data.

3. Advantages of RAID

1. It supports large size logical files that even exceed the limit set by OS
2. It is useful for systems with abundant storage space
3. It optimizes the I/O load transfer among several servers
4. The read/write operation can be parallelized.

Raid 0 is used when we dont require fault tolerance and errors are very less probable

Raid 1 is used when we require higher efficiency and have large budget to buy extra drivers.

Raid 5 is used when we require fault tolerance and maintain consistency

Raid 10 is very costly but packs all the features including fault tolerance and fast rebuild time.