Layer 2 Tracing for (6500, 7609, 4500) Cisco Switches

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In a 6509, 7609 or any Chassis based Cisco switch, to determine where the switch forwards a Source and Destination pair to an actual port in a Port-channel/Etherchannel do the following commands:

Note: Doesn’t apply to Nexus switches.

First enter console for switch:

port-channel hash
Switch# remote login switch
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Great SMTP DNS and Troubleshooting tool

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mxtoolbox

Go to http://www.mxtoolbox.com

This test will list MX records for a domain in priority order. The MX lookup is done directly against the domain’s authoritative name server, so changes to MX Records should show up instantly. You can click Diagnostics , which will connect to the mail server, verify reverse DNS records, perform a simple Open Relay check and measure response time performance. You may also check each MX record (IP ...

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