HTTP monitoring on different port

Service is running on port 5101 but we want to monitor 5100. I have created the health check and added an alias for port 5100 then binded it to the pool. However, the pool is not coming up.

have you tried tcpdump?

 tcpdump -nni 0.0:nnn -s0 -w /var/tmp/output.pcap host x.x.x.x and host y.y.y.y and port 5100 -v

x.x.x.x is non floating self ip on server vlan
y.y.y.y is server ip