Is it possible to make my existing 6509 switch function as a 7600 router? Even if it means purchasing a new sup or other inline card.

I need certain router features, such as q-in-q tag termination.

We need to terminate q-in-q tags from wholesale fiber customers. We have a handover at one site, which I am thinking that I will q-in-q trunk over our own dark fiber using 3750E switches.

Will need to authenticate DHCP option 82; A nice to have would be VPDN, and replace our existing LNS;

  • GRE
  • OSPF
  • BGP

Existing 6500:

cisco WS-C6506-E (R7000) processor (revision 1.0) with 983008K/65536K bytes of memory.

culv-c6506-1#show module all
Mod Ports Card Type                              Model              Serial No.
--- ----- -------------------------------------- ------------------ -----------
  3   48  CEF720 48 port 10/100/1000mb Ethernet  WS-X6748-GE-TX     SAL1105FPGM
  5    2  Supervisor Engine 720 (Active)         WS-SUP720-3B       SAD100202AY

Mod MAC addresses                       Hw    Fw           Sw           Status
--- ---------------------------------- ------ ------------ ------------ -------
  3  001a.a257.d990 to 001a.a257.d9bf   2.5   12.2(14r)S5  12.2(33)SXJ3 Ok
  5  0013.c3a7.ced8 to 0013.c3a7.cedb   4.5   8.5(4)       12.2(33)SXJ3 Ok

Mod  Sub-Module                  Model              Serial       Hw     Status 
---- --------------------------- ------------------ ----------- ------- -------
  3  Distributed Forwarding Card WS-F6700-DFC3B     SAD08320E44  2.0    Ok
  5  Policy Feature Card 3       WS-F6K-PFC3B       SAD100202P5  2.2    Ok
  5  MSFC3 Daughterboard         WS-SUP720          SAD100201BM  2.4    Ok

2 Answers 2


6500 is generally MPLS ready in terms of label support, LDP support and things like VRFs for MPLS VPNs. Some features may be missing because of specific choice of software and hardware.

For example, in your configuration, you'll have very small FIB for services - you have only PFC3B which can hold 256k IPv4 prefixes, or 128k IPv6 prefixes, or half of that for MPLS VPN services (MPLS label takes two entries basically).

Second problem you may hit is the fact that while the 6748 LC you have has MPLS tagging support, it will only do 802.1q tunneling - if you need 802.1q swapping and elastic modifications/etc there is a a whole set of different restrictions (port groups) which you can start to deep dive into here:


Essentially, for 6500 to function as fully fledged metro ethernet edge you'll either need SIP linecards (SIP-200 and SIP-400) or ES/ES+ linecards, which are by itself feature-rich for services like tag swapping, services termination, QoS/HQoS etc. The "LAN cards" as they're called (WS-X6[1357]xx series) are limited in QoS and L2 manipulation flexibility.


such as q-in-q tag termination.

This is going to depend on the line cards you have.

I need certain router features

If you have other that you need, elaborating on which would be good.

Cisco has specific builds of the 7600 software that runs on 6500 chassis, but they are only generally available to customers who have been burned by the 6500/7600 BU split and after much griping to your SE.

  • +1 It is a combination of line card supported features and also the IOS train you are on. There is cross over of features for q-in-q stuff on the 6500's/7600's. Check the IOS features for various 6500 images at Cisco.com
    – Baldrick
    Commented May 21, 2013 at 9:52
  • 2
    I checked the feature navigator and q-in-q vlan tag termination is a feature of the 7600, but does not exist on the 6500
    – rick
    Commented May 21, 2013 at 10:23

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