Addendum:
Some times the network/security teams do not allow you to ping thru firewalls, but you might be able to perform a telnet when connections was configured on the firewall.
In addition to ping you can try a traceroute/tracert (depends on OS) to detect how far the connection is working and where it breaks. But this follows the same rules as ping.
When you are able to access IS Admin via Browser, but no the IS itself (from the same box to the same host:port combination) via Designer, this might be a proxy issue.
Can you check the proxy settings from the Browser and the Designer Settings?
Regards,
Holger
#webMethods#Integration-Server-and-ESB