Latest revision as of 12:20, 15 April 2014

intro

• EIGRP
• OSPF
• Route Redistribution
• BGP
• IPv6

[edit] Administrative distance

                     Administrative 
Protocol 	           distance
Directly connected route          0
Static route out an interface     1
Static route to next-hop address  1
EIGRP summary route ............  5
External BGP                     20
Internal EIGRP ................  90
IGRP                            100
OSPF .......................... 110
IS-IS                           115
RIP                             120
ODR                             160
External EIGRP ................ 170
Internal BGP                    200
Unknown                         255

[edit] Tricks

[edit] Remove * in 'traceroute'

If you get stars in traceroute like below

R1# traceroute 10.0.34.4
 1 10.0.12.2 16 msec 8 msec 12 msec
 2 10.0.23.3 16 msec 16 msec 16 msec
 3 10.0.34.4 16 msec *  20 msec

Look at the rate-limit of icmp: show ip icmp rate-limit

                                  !! the 'show/clear ip icmp' commands are in the
 R4# show ip icmp rate-limit      !! 12.4(2)T train, not the 12.4 mainline train. :)

 DF bit unreachables       All other unreachables   
 Interval (millisecond)     500                       500
 
 Interface                  # DF bit unreachables     # All other unreachables 
 FastEthernet0/1            0                         3

Change (or remove) the rate-limit of icmp

 ip icmp rate-limit 2000
 ! no ip icmp rate-limit unreachable

Source: http://packetlife.net/blog/2008/dec/29/traceroute-timeouts/

This limitation is for the aggregate rate of all the ICMP unreachables, as this output shows. More info in RFC 792.

    type = 3, code 
    0 = net unreachable; 
    1 = host unreachable; 
    2 = protocol unreachable; 
    3 = port unreachable; 
    4 = fragmentation needed and DF set; 
    5 = source route failed.

• CISCO.COM: Using the traceroute Command on Operating Systems

[edit] Robert: fixa route-filter i CNAP / OSPF

router ospf 1
  log-adjacency-changes
  area 13 filter-list prefix FORWARD-PREFIXES out
  network 192.168.31.0 0.0.0.127 area 13
  network 0.0.0.0 255.255.255.255 area 0
  distribute-list route-map LOVELY-ROUTERS-N-ROUTES in
!
!
ip route-map LOVELY-ROUTERS-N-ROUTES permit 10
  match ip route-source LOVELY-ROUTERS
  ip route-map LOVELY-ROUTERS-N-ROUTES permit 20
  match ip address STUDENT-NETS
  ip route-map LOVELY-ROUTERS-N-ROUTES deny 30
!
!
ip prefix-list FORWARD-PREFIXES seq 5 remark *** What routes to send to Mats/hv.se
ip prefix-list FORWARD-PREFIXES seq 10 remark Allow the student network - exactly
ip prefix-list FORWARD-PREFIXES seq 15 permit 193.10.203.128/25 ge 25 le 25
ip prefix-list FORWARD-PREFIXES seq 25 remark Allow all student-added nets w. mask >=28
ip prefix-list FORWARD-PREFIXES seq 25 permit 192.168.31.000/28 ge 28
!
ip access-list standard LOVELY-ROUTERS
remark *** Which OSPF-speakers are allowed in the routing-table
permit ip host 10.1.1.1
permit ip host 10.2.2.2
!
ip access-list extended STUDENT-NETS
remark *** Which trusted student-nets to add to routing-table
remark allow our student-network - exactly
permit ip host 193.10.203.128 host 255.255.255.128
remark allow all student-added networks
permit ip 192.168.31.0 0.0.0.63 255.255.255.255 0.0.0.63
!
!
!

Källa1: http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/routmap.html OSPF Inbound Filtering Using Route Maps with a Distribute List

Källa2: http://www.cisco.com/en/US/docs/ios/12_2t/12_2t4/feature/guide/ftabrt3f.html OSPF ABR Type 3 LSA Filtering