802.1Q Encapsulation Support on Cisco 2600/3600 Series Routers
http://www.cisco.com/en/US/products/hw/routers/ps259/prod_bulletin09186a00800921e4.html
NM-4E
Cisco 261x Cisco 262x/265x Cisco 3600
No No No
Q. What are the differences between the 4-port Ethernet NMs (NM-4E) and the EtherSwitch modules?
A. The EtherSwitch modules are Layer 2 (L2) switches, whereas the NM-4E is a Layer 3 (L3) routing device. All 16 or 36 of the ports on the EtherSwitch modules have a high-speed switch fabric within the NM. This switch fabric enables devices that connect to the EtherSwitch module and belong to the same VLAN to benefit from line-rate switching in hardware. Cisco IOS Software Releases 12.2(15)ZJ and 12.3(4)T can directly associate an IP address with Fast Ethernet or Gigabit Ethernet interfaces on the EtherSwitch module. The feature makes the EtherSwitch module functionally equivalent to the NM-4E, except that the EtherSwitch module has Fast Ethernet interfaces.