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I created above architecture with Mumbai region (I did not select, default value).
When I'm going to lunch the EC2 instance with below VPC, Sub-net and security group attached Im getting below message,
Launch Failed Your requested instance type (t2.micro) is not supported
in your requested Availability Zone (ap-south-1c). Please retry your
request by not specifying an Availability Zone or choosing
ap-south-1a, ap-south-1b.
But when I launch an EC2 instance without attaching VPC, Subnet,s (With default created vpc and security groups) Its launch successfully.
What is the problem? how can I launh EC2 instance with manually created VPC and Subnets.
It looks like t2.micro instances are not available in the particular availability zone. As the message says, You can create instances in the other two AZs.
When you launch the EC2 outside of VPC, it is launching the instances from an availability zone that has the capacity to launch the instance class automatically.
So it does not matter whether you are launching the instance inside the vpc or outside, If you do not specify an availability zone, it will choose a subnet from the availability zone that has the capacity to launch the particular instance class.
Some Availability Zones don't support particular instance types.
Some Availability Zones don't support particular instance types. If you receive the error "Your requested instance type is not supported in your requested Availability Zone," do the following: Determine which Availability Zones support your instance type. Retry the request and specify an Availability Zone that supports your chosen instance type. Or, submit the request without specifying an Availability Zone.
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-instance-type-not-supported-az-error/
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Say I have a DNS Server configured for a URL with a TTL of 5 minutes. The browser will cache the URL to IP address mapping for 5 minutes.
But, if the user clicks on refresh for that URL, will it's corresponding entry in the browser's cache be cleared? Is the browser going to fetch information at the DNS server again?
The case is the following: I need to set a proper TTL to avoid excessive DNS traffic (so it should not be too low), but in the case of VM failure, the traffic should be redirected to another IP address (so it should not be too high).
If a refresh clears the DNS mapping cache entry, then I might choose a higher value.
On clicking the refresh in the browser doesn't query the DNS again, if there is already a cached DNS entry in the browser which is not expired.
If your site relies on DNS failover than in general you shouldn't have anything more than 60 seconds as TTL for your DNS. Please note this is just a suggestion not a full proof way, most of the top 100 websites use this TTL.
HTTP and DNS are on different layers. There is no reason to do a DNS query again if it is in the cache and not expired, when the user requests again some URLs.
DNS, alone, is not a good fail over mechanism. You need to add some kind of load-balancing or master/slave virtual IP handling to have an "immediate" switchover in case of some dead server. Or use IP anycasting. In short, many solutions but even if they can use DNS to their advantage DNS alone can not solve it.
You need to define what amount of time of unavailability is accepted in your setup and based on that it gives you the amount of time/energy/money you can invest on a setup to achieve this fail over.
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I would like to remote into my Pi from outside my home network. The problem is that my apartment provides me with wireless internet and I can't access the router to enable port-forwarding. Is there any way around this? A dynamic dns service perhaps?
I would like to use VNC SSH and/or FTP.
I usually use Team Viewer to remote a station behind NAT without activating port forwarding like in your situation.
You need to create an account on you team viewer application, and register your target station's team viewer to your account.
When you are away, please make sure to always open your target station's team viewer and you will be able remote your target station by first login to your team viewer account. Once you are logged in you will have a list of target station that you have registered. Simply double click one of the list and you can remote your target station.
VNC or SSH will not be able to work behind NAT without activating port forwarding because the router will try to open it's own port instead of your target station.
I was hoping to install Teamviwer in the Raspberry pi as well, and I sent an email off to the temviewer team. This was my response:
Hi Drano
Thank you very much for your message.
Teamviewer does not support ARM architecture. I will forward your suggestion to our product management. Such ideas are always welcome, although I can not promise when or if this Feature will be implemented, as the decision is based on public demand. Nevertheless, your feedback is very important to us as we want to continue to develop TeamViewer based on our user's needs and demands. We will be happy to inform you about realization of this feature.
If you have any further questions on our product, please feel free to contact us.
Best regards,
Harun Rashid
-Support Technician-
P.S.: TeamViewer 9 is ready!
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I had a quick question. I have been reading about elastic IP's with Amazon EC2 instances. I was wondering, a lot of the stuff I do with my server is based on IP limits, like for example google map geocoding which is limited to 2,500 per IP (I beleive it is limited on IP not server).
Firstly, if I have 3 elastic IP's connected to my Amazon EC2 instance, does that mean that effectively my server can appear to be located on three different IP's, so I can effectively triple the amount of google map geocodes I can make?
Secondly, is there a way to determine which IP my server uses, and can this be changed whilst the server is running?
I'm not trying to do anything illegal, I have emailed google about this as well, but it is just to further my knowledge and see if this is possible / legal. Any information would be a great help.
An Elastic IP can only be bound to one running instance. Remapping IPs (for example changing to another IP, or giving the currently used IP to another instance) is possible during runtime.
See the Amazon Feature guide and their FAQs at the bottom.
As a sidenote, I think a lot of Google Maps API request are now on a user-basis (e.g. you have to send a token specific to your account) and not on a per-IP-basis.
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My Configuration: I'm using Windows Server 2008 from VMware(8.0.0) & it's working fine,Now I have 5 Windows 7 system.And I have created Active Directory and DNS (i.e. abc.com).
Issue: Whenever I'm trying to add those systems into a Group,AD can't detect those 5 systems(I mean hostname at all).
To Do(?):
Shall I install DHCP into my server,and then add those client manually,and then it'll show in the Active Directory.
or
I have to create a Network domain which makes the server recognize other 5 systems
Any inputs on this regards making my Active Directory recognize 5 other windows7 client will be appreciated.
Ok long form answer, so its not in Comment.
This is inresponse to the 2 formats out in the market
IPV4 - Oldest current standard for 90% of the NIC's on the market now. 100% of the NIC's will be compliant to this standard
IPV6 - Newest (~2yrs old) and has roughly 50% market implementation.
Acknowledging the industry transition from the IPV4 to IPV6 will help you in solving some DHCP/Network transmission problems. I know of the problem, have tasked the more specialized Network/System Admins with performing this problem solving. I know its a task of inventory control and standardization on the infrastructure.
First off do you have a Single-Node AD or a Farm?
Farm: Do a broad search from the main trunk of AD for the computer.
This will do a full "inventory" search. In the past, the AD implementor didnt setup a default directory for "new" computers and so they went to the top trunk for proper routing. So i would have to do a top-trunk search for the computer, and once found manually drag it to the correct branch or limb.
Single-Node: Follow the same methodology, as above "Farm", but you have less of a headache as your Trunk is more local and not necessarily spread out amongst several locations.
There is always a need for DHCP. Especially if you want to fight against static IP assignment and want to force users to use the Computer Name vs just an IP. Most Servers use Static DHCP for back-door access for administration. In my past Computer management, i have used DHCP to implement and enforce a dynamic IP address for the computer to mitigate anyone from using an IP address as a entry point into your network.
One way to be 100% sure that the computer is not registered in any way with AD:
Login as Local Administrator for all these steps, until otherwise stated.
Disconnect the computer from the network
Change it from Domain to Workgroup (i always use "TEMP" as my Workgroup)
Then do the mandatory reboot.
Rename the computer to another valid infrastructure naming convention
Do mandatory reboot.
During this Reboot, reconnect the Patch Cord back to the NIC (preferably before the Black Windows Loading screen)
Optional Add the new computer name to the needed branch/folder
Login as Local Admin, change from Workgroup to Domain, authenticate with the AD Administrator's credentials
If you error out here, you need to validate that the computer is actually on the network (should have pulled a valid subnet IP address)
If you pulled a non-valid IP address, verify the validity of the Network port and activity on the back of the computer.
Verify the location (if you didnt pre-add the computer at pt 8) and move to the appropriate branch/folder.
Now all of this assuming you are doing this with a Physical Computer.
If you are doing with a Virtual Computer from VMWare, then you will have to verify these points of problems:
VMachines equipment settings, make sure they are similar/same as other valid VBoxes.
Make sure you havent outspent your licensed number of CPU's or Instances
I cant remember if AD is licensed anymore by client licenses or not, or if they just bulked it in with the Server License. They have changed the CAL licensing options so much over the year its hard for implementors to keep track, only the sales people ;)
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I am using virtual machine VirtualBox
Now, I need to limit bandwith. I have 2 Virtual Machines running. One is just for fun. One is for important database access. I need to tell the "fun machine" to just use bandwith on network with less priority if the "database machine" is not using maximum of the bandwith.
I read this
But I am working on Windows.
Would be great if you have any suggestions.
UPDATED
Starting with VirtualBox 4.2, the networking subsystem has support for limiting the maximum bandwidth of a connection. There isn't a graphical user interface for the commands yet so you will have to use the VBoxManage command line to manage the settings. From the manual:
Limits are configured through VBoxManage. The example below creates a bandwidth group named "Limit", sets the limit to 20 Mbit/s and assigns the group to the first and second adapters of the VM:
VBoxManage bandwidthctl "VM name" add Limit --type network --limit 20m
VBoxManage modifyvm "VM name" --nicbandwidthgroup1 Limit
VBoxManage modifyvm "VM name" --nicbandwidthgroup2 Limit
Important Note: VirtualBox only limits outbound traffic from the VM. It does not limit incoming bandwidth. Additional information can be found in the VirtualBox manual, chapter 6 - Virtual Networking: http://www.virtualbox.org/manual/ch06.html#network_bandwidth_limit
ORIGINAL ANSWER
This really is kind of a difficult situation - neither VirtualBox or Windows provide a supported, native way to handle traffic management like you have requested. The good news is that the VirtualBox team is working on a solution to your problem - you may have noticed in recent releases they have added in proper support for CPU usage controls. Hopefully something in the 4.1 or later releases will have the feature you desire.
So what can you do in the mean time? I would suggest looking at programs like NetLimiter that you can run your Window 7 "fun" guest. You will be able to configure all sorts of limits to ensure it doesn't disrupt your overall network access.
What you could do is to create virtual network interface on host and set it in virtual machine network settings as the bridged interface. That would not give you bandwidth limiting yet but you would have separate interfaces for these 2 use cases. Having 2 interfaces will make next step (limiting) easier. I'm not network expert so I can't tell how to limit specific interface, especially on Windows.
Here are some tips, maybe some of them can be applied to your usecase: http://ku1ik.com/2011/11/12/tunnel-vm-network-ssh.html