# Connection error with HTTP challenges

**URL:** https://community.letsencrypt.org/t/connection-error-with-http-challenges/46795
**Category:** Help
**Created:** [November 21, 2017, 8:26pm UTC](https://community.letsencrypt.org/t/connection-error-with-http-challenges/46795 "2017-11-21T20:26:12Z")
**Posts on this page:** 1
**Showing post:** 10

<div class="post-metadata">

### Author: ![fstennet](https://avatars.discourse-cdn.com/v4/letter/f/779978/32.png) [@fstennet](https://community.letsencrypt.org/u/fstennet)
#### Post date: [November 27, 2017, 6:36pm UTC](https://community.letsencrypt.org/t/connection-error-with-http-challenges/46795/10 "2017-11-27T18:36:06Z")

</div>

HAProxy nor Certbot running:

```
~$ sudo ss -tlp
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:ssh *:* users:(("sshd",pid=1232,fd=3))
LISTEN 0 128 :::ssh :::* users:(("sshd",pid=1232,fd=4))

```

**HAProxy** running:

```
~$ sudo ss -tlp
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:http *:* users:(("haproxy",pid=2619,fd=5))
LISTEN 0 128 *:ssh *:* users:(("sshd",pid=1232,fd=3))
LISTEN 0 128 *:https *:* users:(("haproxy",pid=2619,fd=6))
LISTEN 0 128 :::ssh :::* users:(("sshd",pid=1232,fd=4))

```

**Certbot** running:

```
~$ sudo ss -tlp
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:ssh *:* users:(("sshd",pid=1232,fd=3))
LISTEN 0 5 :::http :::* users:(("certbot",pid=2553,fd=8))
LISTEN 0 128 :::ssh :::* users:(("sshd",pid=1232,fd=4))

```

and it looks like sudo can bind to port 80:

```
~$ sudo nc -vvv -l -p80
Listening on [0.0.0.0] (family 0, port 80)
^C

:~$ sudo ss -tlp
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 1 *:http *:* users:(("nc",pid=5397,fd=3))
LISTEN 0 128 *:ssh *:* users:(("sshd",pid=1232,fd=3))
LISTEN 0 128 :::ssh :::* users:(("sshd",pid=1232,fd=4))
```

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