It sounds like the IOS that you are running does not support the 4ESW card. I checked the software advisor on the Cisco site and it looks like 12.3XA is required to support this. I can not be sure from your post whether you are running 12.3(20) mainline code or what. Can you clarify?
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
This document provides configuration tasks for the 4-port Cisco HWIC-4ESW and the 9-port Cisco HWIC-D-9ESW EtherSwitch high speed WAN interface cards (HWICs) hardware feature supported on Cisco 1800 (modular), Cisco 2800, and Cisco 3800 series integrated services routers.
Cisco EtherSwitch HWICs are 10/100BaseT Layer 2 Ethernet switches with Layer 3 routing capability. (Layer 3 routing is forwarded to the host, and is not actually performed at the switch.). Traffic between different VLANs on a switch is routed through the router platform. Any one port on a Cisco EtherSwitch HWIC may be configured as a stacking port to link to another Cisco EtherSwitch HWIC or EtherSwitch network module in the same system. An optional power module can also be added to provide inline power for IP telephones. The HWIC-D-9ESW HWIC requires a double-wide card slot.
This hardware feature does not introduce any new or modified IOS commands.
Feature History for Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
This feature was introduced.
This was a 12.3T feature so you would need at least 12.3.8T or 12.4 mainline version for it to work...
I would check to see if it is even supported on the 1721 or not .
I have a customer who is looking at using a HWIC-4ESW in a 1721 (not yet implemented). I checked the 1721 configuration tool and it indicates that the HWIC-4ESW is supported on the 1721 (assuming a version of code that supports it).
If anyone can state from experience whether the HWIC-4ESW is or is not supported on the 1721 I would be very interested to hear it.
I continue to believe, as you do, that the problem in the original post is that the version of code that they are running does not support this card.
Ok , just didn't see it referenced in the software advisor for that module , the first one they indicate is the 1800 series so I was basing it on that . As you know you get multiple different answers depending on where you look on cco.
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