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Incoming network access to your machines is usually required. Security Groups are how to add network access. If you can't reach your instance by SSH to login or by browser if it runs a Webserver additional Security Group settings could be needed.
Adding Network Access
The default Security Group is empty and no incoming access is configured until you add rules to specify:
- which ports are available for connection to your instance and...
- from which addresses your instance will accept inbound traffic to the open ports
NOTE: If you do not specify a security group at boot the default security group will be applied
- Each rule adds further access, it never cancels or overrides another rule.
- Rules can have overlapping ranges and addresses.
- Rules for the same ports and addresses can be added to more than one Security Group
Removing Network Access
To remove access to a port or from an address locate all security groups with rules relating to that port or address, then
- remove or edit each applicable rule, OR
- do not apply those Security Groups that contain the applicable rule(s)
Pre-Defined and Default Security Groups
For Project Trials ONLY: there are pre-defined security groups for convenience.
- SSH opens tcp port 22 to traffic from all sources (for logging via ssh)
- HTTP opens tcp ports 80 and 443 to traffic from all sources (for web servers)
- ICMP opens all ICMP traffic from all sources (etc. to allow pinging your VMs IP address)
For all other shared projects that are created after an allocation request, there is only the empty 'default' security group at first. These Projects share their security groups so all changes should be made with caution as they may affect instances by other users sharing your Project.
Managing Security Groups
Sometimes it can be convenient to organise rules into multiple Security Groups, for eg
- apply only some or all groups depending on a instances purpose.
- users experimenting with network access can remove groups and re-apply them without re-creating rules each time
- testing rules on a temporary security group and test Instance before adding the same rules to Security Groups already in use.
- rules can appear in more than one Security Group
Applying Security Groups
Security Groups are most conveniently applied before Launching your instance, multiple security groups can be selected.
However Security Groups can also be added or removed on running instances.
Click Launch then click the Security Groups field. The default group is pre-selected
Outgoing traffic on all ports is not blocked.
eg. connections that originate from your instance to the outside world.
Using the Research Cloud creates a publicly accessible server (depending on Security Groups) and therefore that machine can be exploited. All users must read & follow our security guidelines.