The confusing part is this article (amoungst others), but its from 2010. Did the definition change in recent versions?allowguest doesn't allow anonymous SIP calls. It simply shows the activity.
SIP Peers can be used very effectively to protect Asterisk against unauthorised call handling as long as you set the parameter “allowguest=no” in the general section of sip.conf. On FreePBX/Trixbox, this parameter is found on the General Settings page, near the end, and is called “Allow Anonymous Inbound SIP Calls?: no”. When set like this, Asterisk will only accept SIP requests from the pre-defined peer addresses or from peers that authenticate using a valid username and password. Unfortunately, some VoIP service providers may require that you set this parameter to Yes because it suits them to send calls to your PBX from several different addresses (for reasons of load balancing and/or resilience).
I wanted to share the following:
I resolved it by adding hostname to etc/hosts, but only at the end of the first line that starts withMy unqualified host name (ABCD) unknown; sleeping for retry
Maybe related to the above, the below issue is now resolved.
2. Stopping fail2ban takes close to 3 minutes each time.