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All DNS records have a TTL property, specifying the maximum amount of time other DNS servers and applications should cache the record. Setting a DNS record's TTL value to zero, means that applications and DNS servers should not cache the record. When a DNS record is stored in the cache of a DNS server, the record's TTL is continuously reduced as time go by, and when the TTL finally reaches zero the record is removed from the cache. When a DNS server passes DNS records from the cache along to applications and other DNS servers, it supplies the current TTL value - not the original. This way the original TTL is guaranteed no matter how many DNS servers the record passes through. When deciding on the TTL, you need to consider how often the record will be changed. Because of caching, changes to a DNS record will not reach the entire network until the original TTL has expired - a good reason for setting a short TTL. However caching helps reduce network traffic. T...

What is the main purpose of a DNS server? DNS servers are used to resolve FQDN hostnames into IP addresses and vice versa. What is the port no of dns ? 53. What is a Forward Lookup? Resolving Host Names to IP Addresses. What is Reverse Lookup? Resolving  IP Addresses to  Host Names. What is a Resource Record? It is a record provides the information about the resources available in the N/W infrastructure. What are the diff. DNS Roles? Standard Primary, Standard Secondary, & AD Integrated. Secure services in your network require reverse name resolution to make it more difficult to launch successful attacks against the services. To set this up, you configure a reverse lookup zone and proceed to add records. Which record types do you need to create? PTR Records SOA records must be included in every zone. What are they used for ? SOA records contain a TTL value, used by default in all resource records in the zone. SOA records contain the e-mail...

after login in to the switch console #conf t #inter vlan 60   (confiuring vlan 60) #description mainblock   (defining the location) #ip address 10.60.0.3 255.255.0.0  (assiging ip to the Vlan) #no shutdown #conf t #interface vlan 60 #name bravo #wr #conf t #inter range gigabite 0/1 #switch port mode access #switch port access vlan 60 #

Windows Server 2008 Editions, Features and System Requirements Before embarking on the installation of Windows Server 2008, it is important to first gain an understanding of the different editions available and the corresponding hardware requirements. It is also important to be aware of the upgrade options available with each edition. With this objective in mind, this chapter will focus on providing an overview of both the different Windows Server 2008 editions and the recommended hardware requirements. 1. Windows Server 2008 Standard Edition. 2. Windows Server 2008 Enterprise Edition. 3. Windows Server 2008 Datacenter Edition. 4. Windows Web Server 2008. 5. Windows Server 2008 for Itanium Based Systems. Windows Server 2008 Standard Edition Windows Server 2008 Standard is one of Microsoft's entry level server offerings (alongside Windows Web Server 2008) and is one of the least expensive of the various editions available. Both 32-bit and 64-bit versions are available, and in terms ...

HTTP ———- 80 FTP ———— 20,21 TelNet ———- 23 SMTP ———- 25 DNS ———– 53 TFTP ———– 69 SNMP ———- 161 RIP ————- 520 IMAP 4——— 143 IMAP 3 ——— 220 RPC ———— 135 LDAP ———- 389 Net Stat ——– 15 WINS ———- 42 BootP ———- 67 DHCP ———- 68 POP2 ———- 109 POP3 ———- 110 Net BIOS —— 139 SSL(HTTPS) — 443 SQL Server —- 1433 NFS ———— 2049 SSH ———— 22 RAP ———– 38 BGP ———– 179 DNS 53 DHCP client 546 DHCP server 547 FTP 21 POP3 110 SMTP 25 Telnet 23 HTTP 80 1. Which protocol DNS is using TCP or UDP? ANS: UDP 2. Difference between TCP and UDP protocol?

What is an IP address? What is a subnet mask? What is ARP? What is ARP Cache Poisoning? What is the ANDing process? What is a default gateway? What happens if I don't have one? Can a workstation computer be configured to browse the Internet and yet NOT have a default gateway? What is a subnet? What is APIPA? What is an RFC? Name a few if possible (not necessarily the numbers, just the ideas behind them) What is RFC 1918? What is CIDR? You have the following Network ID: 192.115.103.64/27. What is the IP range for your network? You have the following Network ID: 131.112.0.0. You need at least 500 hosts per network. How many networks can you create? What subnet mask will you use? You need to view at network traffic. What will you use? Name a few tools How do I know the path that a packet takes to the destination? What does the ping 192.168.0.1 -l 1000 -n 100 command do? What is DHCP? What are the benefits and drawbacks of using it? Describe the steps taken by the client and DHCP serve...

ILO Setup ILO Setup ILO – Integrated Lights Out This is a very cool feature that allows one to manage the server box remotely. Idea is physically you don’t have to be in the data center to manage servers. ILO interface provides exact same interface as you will see when you have connected monitor, keyboard and mouse to each individual server. Each server comes with default DNS name for ILO web interface (it’s DHCP enabled! so if your network has DHCP IP addresses available, then it will pick up the one for it’s factory default DNS name.) Default DNS names usually in the pattern ILO For example serial id for server is HPPRO1234567, then DNS name to access server using ILO would be ILOHPPRO1234567 and it would be available at http://ILOHPPRO1234567 It comes with default administrator user id / password. This user id/password should be changed immediately in order to make your server secure. Once you login using with given credentials, four tabs that are availab...