Re: Can't Ping Hostnames, but can ping IP addresses

Le 20/02/2025 à 17:17, Brad Stone a écrit :

This may sound like the same post as before, but it's not. :)

I have a client who can ping IP addresses from their IBM i (like 8.8.8.8)
but not host names (like google.com)

It just hangs when pinging a host name vs an IP address which returns
expected results.

They do have 8.8.8.8 and 8.8.4.4 set up as their DNS servers. No host
table entries set up that should cause any problems.

Any ideas what this could be?

To help, they can provide to the network team a trace from the IBM i with the PCAP format that Wireshark can analyze.

https://www.ibm.com/support/pages/how-format-ibm-i-trccnn-and-cmntrc-communication-traces-pcap-files-wireshark-format
https://www.ibm.com/docs/en/i/7.5?topic=ssw_ibm_i_75/cl/strcmntrc.html

I suggest to narrow the trace with STRCMNTRC RMTIPADR('8.8.8.8') on one shot then STRCMNTRC RMTIPADR('8.8.4.4') on another shot. It looks like DNS traffic is blocked somewhere.

Bradley V. Stone
www.bvstools.com
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