could not connect aws elasticache redis from .net app - amazon-web-services

Question

I am connecting .NET core app to AWS ElastiCache Redis.
The AWS Elasticache Redis is running and port 6329 is open on security group. The client code is using StackExchange.Redis:
var redis = ConnectionMultiplexer.Connect("redis-1.xxxx.0001.use1.cache.amazonaws.com:6379");
//var redis = ConnectionMultiplexer.Connect("localhost"); //working
IDatabase db = redis.GetDatabase();
string value = "abcdefg";
db.StringSet("mykey", value);
string value2 = db.StringGet("mykey");
Console.WriteLine(value2); // writes: "abcdefg"
Console.ReadLine();
Exception is:
It was not possible to connect to the redis server(s). UnableToConnect
on redis-1.xxx.0001.use1.cache.amazonaws.com:6379/Interactive,
Initializing/NotStarted, last: NONE, origin: BeginConnectAsync,
outstanding: 0, last-read: 5s ago, last-write: 5s ago, keep-alive:
60s, state: Connecting, mgr: 10 of 10 available, last-heartbeat:
never, global: 0s ago, v: 2.0.601.3402
Added to ,abortConnect=false to the endpoint, I am able to connect.
Now the error is at StringSet
StackExchange.Redis.RedisConnectionException: 'No connection is
available to service this operation: SET mykey; UnableToConnect ...
The .NET code is working fine with my local Redis service so looks like something incorrect with my AWS setup.
Successfully ssh to my EC2-instance and redis-cli to my AWS redis service:
Any idea please?
NOTE: AWS Elasticache Redis is NOT available for public access as default.
https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/accessing-elasticache.html#access-from-outside-aws
Can you connect to Amazon ElastiСache Redis outside of Amazon?

Answer 1

Question: "...port 6329 is open on security group.." Dont you mean 6379?
Even that, i think i cn have an issue on the "default" subnet groups.
Does the VPC_Subnet (in that group) where the AWS ElastiCache Redis is, has a Routing Table with access to the Internet Gateway?
If not, you need to attache the InternetGteway to the Route Table and than use that Route Table on the Subnet that you want.
It should be like the pick:
Internet GW