# Https messaging fails, communication error between HPC and cylc hosts **URL:** \ **Category:** Cylc Support\ **Created:** [September 23, 2020, 12:33pm UTC](https://cylc.discourse.group/t/https-messaging-fails-communication-error-between-hpc-and-cylc-hosts/273 "2020-09-23T12:33:06Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\ **Post date:** [September 23, 2020, 4:04pm UTC](https://cylc.discourse.group/t/https-messaging-fails-communication-error-between-hpc-and-cylc-hosts/273/3 "2020-09-23T16:04:05Z")
Hello, Ok, lots going on here, lets start looking at local comms and get that sorted before moving on to remote issues. The following error from the GUI is curious: > [@fredw](#): > > Cannot connect: [https://localhost:43015/poll\_tasks:](https://localhost:43015/poll_tasks:) (‘Connection aborted.’, error(104, ‘Connection reset by peer’)) To locate a running suite Cylc uses the contact file (located in `~/cylc-run//.service/contact`). This message suggests that `CYLC_SUITE_HOST` is set to `localhost` in that file which, if true, is likely the issue. I would expect this to be set to the [FQDN](https://en.wikipedia.org/wiki/Fully_qualified_domain_name) for that host (i.e. `hostname -f`). Could you check the contact file of a running suite to see what `CYLC_SUITE_HOST` is set to as it could be to do with host self-identification. Also check the output of `hostname` and `hostname -f`. Typically these two should match: ```console $ hostname $ python2 -c 'import socket; print socket.gethostname()' ``` As should these two: ```console $ hostname -f $ python2 -c 'import socket; print socket.getfqdn()' ``` Oliver --- _[View the full topic](https://cylc.discourse.group/t/https-messaging-fails-communication-error-between-hpc-and-cylc-hosts/273)._