HaProxy Validates Websocket DNS lookup backend but not ipaddress

Hi,

I am configuring my haproxy instance before all my backend servers are alive. For the configuration below If I use a not yet existing ip address all starts fine however if I use a DNS lookup entry e.g. myserver.com it attempts to resolve this and fails to start with “invalid address” error

  1. Can i turn off this validation?
  2. Why does it validate DNS and not ipaddress?

Many thanks, config below
W


Checks the path for Websocket CLI service

acl webscktcli_app path_beg /wsktcli-websocket
acl webscktcli_app hdr(Upgrade) -i WebSocket
acl webscktcli_app hdr_beg(Host) -i ws
use_backend bk_websktcli_websocket if webscktcli_app


failing backend config with URL (mywebskt.com)

#---------------------------------------------------------------------

Backend for Websocket CLI

#---------------------------------------------------------------------
backend bk_websktcli_websocket
mode http
balance roundrobin
option forwardfor
timeout tunnel 60m
reqadd X-Forwarded-Proto:\ https
cookie myCookie prefix nocache
server wsktcli-1 mywebskt.com:8080 cookie S1 check

working backend config with dummy ipaddress (4.4.4.4)

#---------------------------------------------------------------------

Backend for Websocket CLI

#---------------------------------------------------------------------
backend bk_websktcli_websocket
mode http
balance roundrobin
option forwardfor
timeout tunnel 60m
reqadd X-Forwarded-Proto:\ https
cookie myCookie prefix nocache
server wsktcli-1 4.4.4.4:8080 cookie S1 check