AVINASH GADGE, Infrastructure Solutions

Fantastic site!   This site is owned by CISCO and we all know CISCO is most reputed network appliance, Firewall providers.   http://www.senderbase.org/  Above site servers as largest email and web traffic monitoring network, apart from this it rates the domain on the basis of their activity and as we discuss in our last post (SMTP) you need to add (External Parties) Mx Record (SMTP server Name/IP) to DNS.   This site become handy to judge external party and take decision whether we should allow that entity to send direct email to our users as this site shows is this SMTP is sending SPAM/Malware etc.  Please have a look yourself..!    http://www.senderbase.org/   Thank you Cisco for wonderful tool/site.  

What is SMTP? Simple Mail Transfer Protocol for electronic message which works on Port-25 https://tools.ietf.org/html/rfc821   (1982) https://www.ietf.org/rfc/rfc5321.txt (1998) How it works ? If you want to send email out of your organization you need to have MX record of particular receivers listed on your dns. Now what happen when we send email? It goes to our SMTP Server and if we are sending email outside SMTP server queries to DNS if it has MX record for receivers. DNS provide necessary information to SMTP server and here actual conversation start between 2 parties.       Send SMTP Server connect Receivers SMTP Server on Port 25 For example (Mail. *****.Com Port 25) Receiver SMTP Server: Send acknowledge by sending ELHO command. Sender SMTP Server: - Mail from 123@XYZ.com Receiver SMTP Server: - 250 (OK) Sender SMTP Server: - Recipient Mail ABC@*.com Receiver SMTP Server: - 250 (OK) Sender SMTP Server: - DATA Receiver SMTP S

Hello Friends, I have come across lot of administrators who face difficulties while working on mount points. Let’s discusses what mount point is? A mount point is a   directory   in a   file system   where additional information is logically connected from a storage location outside the operating system’s root drive and partition. Now who you will troubleshoot ntfs corrupt problems on mount points where you don’t have drive letter? Ok… Use mountvol command and it will show you all mount points hosted on your server or system copy Guid which it shows for example “  \\?\Volume{78aecb7a-1a16-4e3b-9cdd-0b9e5a4ea2b0} ” this shows you mount path also. Now run Chkdsk /F  “Guid”

Interesting things related to SCOM. Today one of my colleague came to me stating she got scom alert when disk space was 1% instead she should get on 10%. Ah! That was something new for me and I was surprised how this happened hence thought lets investigate at what threshold alert was sent. 1 St I tired checking server health explorer and see what threshold are set and then went to check overrides. This one gave me information what has set but didn’t answer my question why at 1%. So took new way that is again went to Windows computer under monitoring tab, Searched for server, than opened Performance Chat and selected legend % logical disk free space and on right side set Time range 3 days. It took few seconds and gave me graph how disk was consumed than on the graph right clicked and selected “Show Alert” which shown me what time alert was initiated and how quickly disk got filled.

Hello Friends, Production Services you might have heard one word Disaster recovery and we before going to DR we should understand few basic steps and then we will move towards DR. Backup Strategy: 1)       Backup Method 2)       Backup Window 3)       Retention Period 4)       Recovery Method What is RPO and RTO? RPO: Recovery Point Objective How much data you can afford to lose (Or how long it has been since you saved your data, the recovery point) RTO: Recovery Time Objective  It is the length of time you can afford to take to return to normal service. Technologies can be used for RPO and RTO? Recovery  Point (RPO) Tape Backups Snapshot Asynchronous replication Synchronous replication Recovery Time (RTO) Bare Metal Restore Disk Restore Tape Restore Role difference between Master Media and EMM? Media Server: These servers had some form of storage attached either network storage,  Physical  storage or tape  l