Interface Naming Convention

[cyee]

I recently configured a couple of 1841 routers and used SDM instead of doing it manually. I'm a bit confused as to the naming conventions "chosen" by SDM:

The routers each had a 1dsu WIC in slot 0 and a vanilla 1T in slot 1. SDM named them:

Serial0/0/0 (1dsu)

Serial0/1/0 (1T)

I had been expecting Serial0 and Serial1.

I don't intend to change them, but would appreciate an explanation of the logic behind the "selection". (Could not find docs on CCO.)

TIA

[thisisshanky]

You cannot change them.

This link explains in detail.

http://www.cisco.com/en/US/products/hw/routers/ps282/products_tech_note09186a008035b051.shtml

[cyee]

Shanky (hope your'e not a golfer), thanks for the helpful reference.

Concluding question:

If I want to define a subinterface on S0/0/0,

Would it be S0/0/1, or S0/0/0.1, or S0/0/0/1 or ???

TIA

[Richard Burts]

Curt

I was on a logical path to the answer. Sankar found an excellent link which gave a good technical explanation. I believe that the answer to your concluding question is that a subinterface would be s0/0/0.1. (subinterfaces are always a .x of the major physical interface).

I believe that s0/0/1 would be a different physical interface. And s0/0/0/1 is an entity that logically does not exist.

HTH

Rick

[Richard Burts]

Curt

I do not know that I have ever seen it written anywhere but I believe that the sinmple integer names like serial 0 and serial 1 were developed especially for the fixed configuration routers where the position of the network cards was fixed and permanent. Cisco developed a more complex and sophisticated naming convention especially for routers with card slots where cards can be inserted and removed and moved around, Cisco generally uses names with x/y format so they can identify which slot and which card element.

HTH

Rick