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Tuesday, December 12, 2017
Lab Gear * Routers * 3600 (3640)

3640 Routers


The Cisco 3600 series routers were commonly used as WAN distribution routers in the 1990’s and into the early 2000’s. Three main models existed: 3620, 3640, and 3660, with the 3rd digit identifying the number of Network Module (NM) slots (2, 4, or 6, respectively). The 3640 happens to support later IOS versions than do the 3620 and 3660, making the 3640 in particular have some appeal as a used router for Cisco exam preparation. It also supports MPLS VPNs as both Provider (P) and Provider Edge (PE) router.  

Popularly sold as new in years:
End-of-Sale (EOS) years:
Most Recent mainline IOS supported
Most recent T-train IOS supported
Max Flash


Supported Feature Sets Referenced by Other Pages on this Site

  1. IP
  2. IP Plus


Cisco originally offered the 3640, and later the 3640a, with identical hardware features from the customer perspective. The 3640/3640a routers have 4 NM slots, but no built-in network interfaces. To have interfaces, you must have at least one Network Module (NM). Several NMs exist that include both a LAN interface and slots for WICs.
The following table lists some commonly-used NMs:

  Built-in WAN Built-in LAN
2 WIC slots (supports WIC-1T, not 2T)
1 10BaseT (RJ-45)
2 WIC slots
1 10/100 (RJ-45)
2 WIC slots
2 10/100 (RJ-45)
4 low speed serial
8 low speed serial
16 low speed serial
2 interfaces, with octal cable for 16 async ports
4 interfaces, with octal cables for 32 async ports
16 10/100 (RJ-45)


Cables and other Notes

  • Several NMs supply a LAN interface or two, plus 2 WIC slots. Popularly, buying a 3640 with a single such NM, plus 1 or 2 WICs, makes the 3640 very functional for routing tasks.
  • Note the restriction on 3640's with a NM-1E2W - as confirmed by the community, this combination supports only WIC-1T's, limiting the number of serial interfaces.
  • With an Ethernet Switch module (NM-1ESW), the 3640 can also act as a LAN switch, with configuration very similar to a layer 3 LAN switch – for typically less money than an actual Cisco layer 3 switch.
  • For higher serial port density, three of the listed NMs support Async/Sync ports (4, 8, or 16 interfaces), which support synchronous speeds up to 128 Kbps, but for configuration practice, there are no differences compared to the higher speed serial interfaces on a WIC-2T. The 4 and 8 port cards use the same DB-60 connectors as a WIC-1T, and the 16 port card uses the same connector as the WIC-2T cards.
  • The NMs with async ports are popular so that the 3640 can be used as a console access server.
  • The 10/100 ports on the NMs support 802.1Q. The 10BaseT interface does not.
  • The following link is a great reference for the 3640 NMs: http://www.cisco.com/en/US/...interfaces_and_modules.html
  • 3600 Series architecture doc




Known items that need research or verification

  • End-of-Sales years and links to the EOS notices.

Change History

Feb 23, 2010 – Version 1.0
April 22, 2010 - Version 1.1 - Added notes about NM-1E2W not supporting WIC-2T.
April 26, 2011 - Version 1.2 - Changed links to not require partner login; added links, included EOS announcement.


 Router Series