How to test port connectivity on machine with two Ethernet ports?

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Level 1

49 points

How to test port connectivity on machine with two Ethernet ports?

Hi Folks,

I have a server with two NIC cards, and two IP addresses (one public, one private).

How can I test that my public-facing port has connectivity to the outside world? Can telnet or another tool be used to force the query to go via one specific port?

Many thanks for your ideas, suggestions.

Doug

Mac OS X (10.5.7)

Posted on Jun 8, 2009 8:53 PM

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Answer 1

Jun 9, 2009 3:39 AM in response to Doug Niven1

Would a trace route to somewhere on the Internet work?

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Answer 2

Jun 9, 2009 5:33 AM in response to Doug Niven1

The Network Utility should give some help - look at the routing tables, for example. Simplest, if there is no internet access via the private port, would be to use ping to an internet address. In the first instance ping the router/gateway address associated with your public IP address.

AK

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Answer 3

Camelot

Level 9

54,333 points

Jun 9, 2009 8:26 AM in response to Doug Niven1

How can I test that my public-facing port has connectivity to the outside world?

Ping our router address, or ping any non-local site. As long as your default route is setup correctly it will go over the public link.

Can telnet or another tool be used to force the query to go via one specific port?

All protocols use the underlying routing table to determine which link to use.

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Answer 4

Doug Niven1 Author

Level 1

49 points

Jun 10, 2009 9:55 PM in response to Doug Niven1

Hi Folks,

Indeed the problem was a default route.

For others with two NIC cards in similar situations, here's what I did:

en0: has public IP, subnet mask, gateway,
en1: has private IP, subnet mask, NO gateway

Works like a champ now.

Cheers, Doug

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