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 Posted: Sunday Aug 3rd, 2014 07:00 am
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ident



Joined: Wednesday Aug 9th, 2006
Location: Singapore
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Discovery of ETH03 in Comfort Server Manager - Technical Information

Comfort Server Manager uses UDP Port 30303 to discover the ETH03 IP address
ETH03 will reply to the query also using UDP Port 30303

The screenshot below is from Wireshark, which is a useful free tool  for network troubleshooting



Set "Promiscuous mode" on Wireshark
Apply filter UDP==30303 to the captured packets

In line 110,  Comfort Server Manager running on the PC (192.168.1.2) sends a broadcast  on UDP port 30303 to destination port 30303

In Line 111, the ETH03 replies on UDP port 30303 to destination port 30303 of the querying IP address. Its IP address (source ) is 192.168.1.204

Hence if UDP port 30303 is blocked on the router or switch or PC, there will be no reply from the ETH03 and the discovery will not work

Note that Comfort Server Manager will send the discovery broadcast only Once (it may repeat  the request if there is no reply). If there is no reply after repeating, it will not broadcast again, unless the Refresh button is pressed on Comfort Server Manager.

Try disabling all Firewalls which may be blocking the UDP port

If the ETH03 IP address appears and disappears repeatedly, this is due to a network error, which is probabaly caused by a loop in one of the switches or network devices. Note that this condition was actually seen at a site. This problem is not caused the ETH03 or Comfort Server Manager


Last edited on Saturday Jan 3rd, 2015 12:13 pm by

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