RIP Lab Tips

  • Show key chain and show ip protocols to see authenentication stuff.
  • Watch for spaces / trailing spaces e.g. show run | inc Cisco$ or Cisco $
  • Show ip protocols to check for filters and timers etc and passive interfaces.
  • Debug ip rip may show auth and version mismatches ete.
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Frame Relay Lab Tips

  • Shut down port first and then configure – this can help against unwanted dynamic maps.
  • Set the hub as the DR for everything e.g. PIM, OSPF.
  • Inverse arp and no arp frame to avoid dynamic entries.
  • Show frame map and make sure nothing says ‘dynamic’. If it does, do ‘clear frame map’, reload or remove the encapsulation frame-relay command which removes everything!
  • No Need to do ‘BROADCAST’ from spoke to spoke if going via hub.
  • enable frame-relay switching in global configuration for switching.
  • frame-relay intf-type dce required on the FR Switch to bring the line protocol up.
  • RIP –

– Check hub has broadcast option on map to each spoke.

– Disable split horizon on hub for spoke to spoke comms or – Neighbour statements or GRE tunnel!

RIPv2 Written Notes

These are my ‘crib notes’ that I’ve made to serve as a last minute refresher. Please forgive the grammer / spelling as I did not develop these notes with publishing in mind.

RIP & Distance Vector

*** Theory ***

  • Ripv2 – adds MD5 Authentication, External route tags, Multicast route updates and VLSM
  • Interface – configure rip version on per interface basis with config-if ip rip ?
  • Passive-interface
    • Rip – stops RIP updates being adverstised out of that interface
    • Neighbours – use this if you cant use multicast updates
    • Offset list – use this to manipulate metric
    • Distibute list – create an access list with routes you want to hide and then attach to rip via distribute-list [access list] out
    • Redistribute –
      • RIP into EIRGP – You must specify metric so redistribute rip metric 1500 0 255 1 1500
      • Eirgp into RIP – redistribute eirgp 2000 metric 2 (2 hops away)

*** Commands ***

 

Route Redistribution Crib Notes

These are my ‘crib notes’ that I’ve made to serve as a last minute refresher. Please forgive the grammer / spelling as I did not develop these notes with publishing in mind.

Route Redistribution

***theory***

  • IGRP – Automatically redistributes with EIGRP under the same AS number
  • RIP – You must specify a seed metric other it takes it as 16 – invalid
    • E.g. Redistributed connected metric 2
    • OSPF – Default seed metric is 20 and type E 2, unless it BGP then the metric is 1
      • E.g. redistributed connected subnets
      • Must use subnets in order to get the subnets
      • Type 2 – fixed cost from ABR to destination (default)
      • Type 1 – Cost from local router
      • Default-Information Originate
        • Always – ASBR will always be Default route
        • Not always – ASBR will be default route only if default route is in routing table
        • EIGRP – When redistributing you must specify the 5 k or use default metric
        • Pitfalls – if you see a route in the table, it may not be able to reply if no 2-way redis
        • No seed metric on default for RIP, IGRP, EIGRP, ISIS is 0 – YOU MUST SPECIFY
        • Best Practice – redistribute connected
        • Sub optimal routing: Change AD, Route Metric and use distribute lists
        • Show IP protocols – best for route redistribution & verify on ASBR

  • Route Map: can be used for Policy Based Routing.  Andy DENY clause does not drop packets. If you want to drop it, match the IP address and set interface to null0
  • Passive Interfaces – Accepts routing updates but do not send them
    • OSPF – This will stop the interface from forming a relationship i.e. no hellos
  • Null0 – appear in routing table after manual route summarisation.
  • Distribute list – ACL used for route filtering