# Exception caught on transport layer (es6.4.2)

**URL:** <https://discuss.elastic.co/t/exception-caught-on-transport-layer-es6-4-2/163924>\
**Category:** Elasticsearch\
**Tags:** elastic-stack-security\
**Created:** [January 11, 2019, 3:51pm UTC](https://discuss.elastic.co/t/exception-caught-on-transport-layer-es6-4-2/163924 "2019-01-11T15:51:37Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![aparent](https://avatars.discourse-cdn.com/v4/letter/a/9de0a6/32.png) [@aparent](https://discuss.elastic.co/u/aparent)\
**Post date:** [January 14, 2019, 1:09pm UTC](https://discuss.elastic.co/t/exception-caught-on-transport-layer-es6-4-2/163924/7 "2019-01-14T13:09:12Z")

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When I use the ES/Hadoop API I don't specify the client's key and certificate, yet, it works with SSL/TLS enabled.  
I don't understand why I would add parameters in the transport client if they are optional in another API ?  
Please, correct me if I'm wrong so I can understand my mistake !

Again, thank you !

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_[View the full topic](https://discuss.elastic.co/t/exception-caught-on-transport-layer-es6-4-2/163924)._