sub-interface and secondary

haitmale

now, I'm not looking to be spoon fed here, I just can't seem to find a resource that clearly defines the difference between these two. When configuring IPX, what is the functional difference between setting up a secondary network on an interface or using subinterface.
Give me a clue if you have it.
thanks.

cctrainer

Sub-interfaces are the 'new' (post IOS 11.3 or so) way of assigning multiple network addresses. There is very little difference between the two, however sub-interfaces allow VLAN tagging and secondary addressing does not. Sub-interaces also allow the IOS to track interface stats and the state of the interface. For eg - using 'sh ip int brief' would show all sub-interfaces but not any secondary addresses.

Hope this helps