Router configuration partitioning

If you have to troubleshoot routers with long configurations, you're probably as fed up with the slow response of the show running-config command as I am. Unfortunately, there's not much you can do; the running configuration is reverse-engineered from various memory variables every time you ask for it and that process simply takes time if you've configured many parameters.

IOS release 12.2(33)SRB has introduced a fantastic feature: router configuration partitioning. The early seeds of this idea are already present in mainstream IOS releases. For example, you can display the configuration of a single interface, all class-maps or all policy-maps. The configuration partitioning gives you the ability to display access-lists, route-maps, static routes, router configurations ...The following printout shows you the various parts of router configuration you can display:

PE-A#show running-config partition ?
  access-list All access-list configurations
  class-map All class-map configurations
  common All remaining unregistered configurations
  global-cdp All global cdp configurations
  interface Each Interface specific Configurations
  ip-as-path All IP as-path configurations
  ip-community All IP community list configurations
  ip-domain-list All ip domain list configurations
  ip-prefix-list All ip prefix-list configurations
  ip-static-routes All IP static configurations
  line All line mode configurations
  policy-map All policy-map configurations
  route-map All route-map configurations
  router All routing configurations
  snmp All SNMP configurations
  tacacs All TACACS configurations
For example, if you want to display just the configuration of the OSPF process, you'd ask for show running partition router ospf 1:
PE-A#show running partition router ospf 1
Building configuration...

Current configuration : 164 bytes
!
Configuration of Partition - router ospf 1
!
!
router ospf 1
 log-adjacency-changes
 passive-interface Serial1/1
 network 0.0.0.0 255.255.255.255 area 0
!
!
end

8 comments:

  1. Hvala Pipi, tole bo lepo olajsalo dolocene stvari.

    ReplyDelete
  2. Very interesting.
    Just wondering....does the ospf output include any interface specific config too?

    ReplyDelete
  3. strange thing.....it seems that my ios version doesn't support this feature... but, but, but... I have quite new ios :D

    c181x-advipservicesk9-mz.124-15.T3.bin

    rtr#show runn ?
    all Configuration with defaults
    brief configuration without certificate data
    class-map Show class-map information
    flow Global Flow configuration subcommands
    full full configuration
    interface Show interface configuration
    linenum Display line numbers in output
    map-class Show map class information
    policy-map Show policy-map information
    ssid Show Dot11 SSID information
    view View options
    vlan Show L2 VLAN information
    | Output modifiers

    ReplyDelete
  4. Is this just a rollup of the "section" output modifier?

    ReplyDelete
  5. @tassos: no, the "show running router xxx" contains only the routing process configuration.

    @anonymous: This feature only works in 12.2SRB/C. It's not yet integrated in 12.4.

    @aaron: the "section" output modifier is a grep-like filter that is applied AFTER the output is already generated, which can take a long time if you have large configuration. The "show running xxx" command generates just the necessary part of the router configuration and is thus significantly faster.

    ReplyDelete
  6. "This feature was introduced in software images for the Cisco 7600 series in Release 12.2(33)SRB"

    Probably should have included that piece of important information. :|

    ReplyDelete
  7. It works on a 7200 in 12.2(33)SRC. You didn't think I have a 7600 to play with, did you?

    ReplyDelete

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Ivan Pepelnjak, CCIE#1354, is the chief technology advisor for NIL Data Communications. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.