wmfaris
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Security Group Policy Inbound Connection

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More Posted time:Mar 8, 2018 11:33 AM
Hi All,
From my understanding, in order ECS within same VPC (intranet) to communicate between them we need to put them in the same security group. By default firewall policy for inbound is deny all and outbound is allow all. Someone can verify this?
My question is if there is incoming external connection to communicate with one ECS only (lets say using port 443), so we need to create a new security group that is applicable to that particular ECS and create firewall rule with priorty that is lower than previous security group?


Thanks,
Faris

abdulhafeez
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1st Reply#
Posted time:Mar 8, 2018 14:00 PM
My question is if there is incoming external connection to communicate with one ECS only (lets say using port 443), so we need to create a new security group that is applicable to that particular ECS and create firewall rule with priorty that is lower than previous security group?

Answer: Consider VPC as a virtual network for IP range192.168.0.0/16, inside that VPC you can create mutliple vSwitches (VLANs).. for example: vSwitch-1 for subnet 192.168.1.0/24, vSwitch-2 for subnet 192.168.2.0/24,  and vSwitch-3 for subnet 192.168.3.0/24, and so on.... all these subnets will be able to communicate with each other..
Now about security groups: Consider SGs as firewall, if you want to allow certain traffic (lets say port 443), create new SG wth allow port 443, and add ECS to that SG, you can remove that ECS from default SG.

Let me know your feedback..

Thanks
Abdul Hafeez

wmfaris
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2nd Reply#
Posted time:Mar 8, 2018 18:54 PM
"Consider VPC as a virtual network for IP range192.168.0.0/16, inside that VPC you can create mutliple vSwitches (VLANs).. for example: vSwitch-1 for subnet 192.168.1.0/24, vSwitch-2 for subnet 192.168.2.0/24,  and vSwitch-3 for subnet 192.168.3.0/24, and so on.... all these subnets will be able to communicate with each other"
Thanks again for the response @abdulhafeez, but from my reading through alibabacloud user guides we have to create security group that contains all ECS so that they can communicate each other. Creating vSwitches or VLANs only  not enough to enable communication between them.  Unless you have tested in real console then I accept your statement, can you verify this?


"Now about security groups: Consider SGs as firewall, if you want to allow certain traffic (lets say port 443), create new SG wth allow port 443, and add ECS to that SG, you can remove that ECS from default SG."
If i removed default SG, I think It cannot communicate with other ECS. Have you tested it?


THANKS



abdulhafeez
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3rd Reply#
Posted time:Mar 8, 2018 21:13 PM
You have to make all ECS part of same custom SG that you are creating,, then you can remove default SG from each instance. Configure rules as per need on custom SG for communication between ECS instances.

wmfaris
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Posted time:Mar 9, 2018 0:14 AM
abdulhafeez:You have to make all ECS part of same custom SG that you are creating,, then you can remove default SG from each instanc...回到原帖
Seem now I got your idea, will test that out..THANKS

abdulhafeez
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Posted time:Mar 9, 2018 0:25 AM
Sure.. good that got the idea.. pls share the outcome of testing.

BrianBae
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Posted time:Jul 11, 2018 17:09 PM



Please check this picture.

Ranjithkumar
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Posted time:Jul 13, 2018 13:48 PM
Hi @wmfaris,  Yes you need to create a new security group which is also the best way to do that.
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