Adventures in IP Default-network


here goes>>>   BB3 is connected to R6 over a serial link with the network 54.1.1.0/24 between them

the setup below..the actual question the very bottom



router 6




Rack1R6(config)#ip default-network 54.1.1.0


********this generates the static summary ie ip route 54.0.0.0 255.0.0.0 54.1.1.0 as shown below***********
 

---------------------------------------------------------------------------------------- 

 

Rack1R6(config)#do sh run | i ip route

ip route 54.0.0.0 255.0.0.0 54.1.1.0


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*****at this point the summary should be in the routing table and gateway of last resort is not set as there is no candidate default(since we dont see a * next to the static******

Rack1R6#show ip route | i S


 

S       54.0.0.0/8 [1/0] via 54.1.1.0

 



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*****now i add the classful entry of the ip default network since the other cmd ws just for creating the static*****

 

 

Rack1R6(config)#ip default-network 54.0.0.0

 


AAAAND VOILA

 

     

 

 

 

 

Rack1R6(config)#do show ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

 

Gateway of last resort is 54.1.1.0 to network 54.0.0.0

 

     155.1.0.0/16 is variably subnetted, 8 subnets, 2 masks

C       155.1.146.0/24 is directly connected, FastEthernet0/0.146

R       155.1.9.0/24 [120/2] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

R       155.1.13.1/32 [120/2] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

R       155.1.13.0/24 [120/2] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

R       155.1.7.0/24 [120/1] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

R       155.1.37.0/24 [120/1] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

R       155.1.79.0/24 [120/1] via 155.1.67.7, 00:00:08, FastEthernet0/0.67

C       155.1.67.0/24 is directly connected, FastEthernet0/0.67

     54.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C       54.1.1.0/24 is directly connected, Serial0/0/0

S*      54.0.0.0/8 [1/0] via 54.1.1.0

     150.1.0.0/24 is subnetted, 4 subnets

 --More--

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THE QUESTION>> WHY dont i see a 0.0.0.0 route in RIP on the other routers ie RIP is not picking it up????







«1

Comments

  • Brian tested this as well in RIP Default Routing ATC and it was not working. Most likely because this is a legacy command.

  • yep...i wasted half a day..thats 6 hours on it

     

    i should been almost done reading the EIGRP section of doyle by tonite so i coulda started on EIGRP  WB1 tomorrow

     

    today ws the closest i have come to wanting to punch my monitor :-(

  • hi,

     

    the concept for ip default-network is actually not to insert 0.0.0.0 route istead that route that we specify in that command will act as a default route. so whoever is the originator of that specific route (in your case R6) will get all the traffic for destionation that do not have specific routes in routing table. and the best practice is to always use it on edge router.

     

    Hope this helps.

     

     

  • the concept for ip default-network is actually not to insert 0.0.0.0 route istead that route that we specify in that command will act as a default route. so whoever is the originator of that specific route (in your case R6) will get all the traffic for destionation that do not have specific routes in routing table. and the best practice is to always use it on edge router.

    Oh yeah, I missed out that 0.0.0.0. It's supposed to be RIP route marked with asterisk "*". But even this didn't happen when Brian tried it in ATC.

    ToxicAvenginator, did you see asterisk "*" beside the route in the other router?

  • hi,

     

    the concept for ip default-network is actually not to insert 0.0.0.0 route istead that route that we specify in that command will act as a default route. so whoever is the originator of that specific route (in your case R6) will get all the traffic for destionation that do not have specific routes in routing table. and the best practice is to always use it on edge router.

     

    Hope this helps.

     

     

     

    http://www.cisco.com/en/US/docs/ios/12_3/iproute/command/reference/ip2_i1g.html#wp1037313

    If the router has a directly connected interface onto the specified network, the dynamic routing protocols running on that router will generate (or source) a default route. For Router Information Protocol (RIP), this is flagged as the pseudonetwork 0.0.0.0; for Interior Gateway Routing Protocol (IGRP), it is the network itself, flagged as an exterior route.

  • no guys no..it does not work..and as noted above..it should source a quad zero default from RIP..the cisco doc says so

     

    there are 2 ways of doing this

    1) if the route you r trying to flag and inject as a default >>

    a)is connected to your router>>> do a ip default network cmd for the network with the same mask as you have on your router (classless)..this generates a  wierd static in your routing table that cannot be deleted

    b) do a classful ip default network statement

    and voila you see it flagged as the gateway of last resort...

    8****the problem is that RIP dosen't wanna pick it up

     

    2) if the route is not local...ie you r receiving it from another router...then just do a classful default network statement

    below is brians blog on it

     

    http://blog.ine.com/2008/01/15/issues-with-the-ip-default-network-command/

    brians explaination makes sense and it seems to wanna work in that way...but falls short..

  • Hi all,

      I remember i also had a fight with this feature. :) So, ip default-network works only for DV protocols (RIP,IGRP,EIGRP); for all, the network advertised with command "ip default-network" needs to be classfull(ip default-network 2.0.0.0 and NOT ip default-network 2.2.2.0).

    For RIP, the network that you flag as candidate for default route, does not need to be advertised through RIP (it can be but it is not required). As RIP does not understand the "candidate default" flag in RIP updates, the router on which "ip default-network" is configured advertised a 0.0.0.0/0 route out on its RIP enabled interfaces. The requirement to do this, is to have at least one subnet from the major prefix in its routing table(note in the bellow example i have 2.2.2.0/24 on my interface, not 2.0.0.0/8)

    R5:
    interface FastEthernet0/0
     ip address 1.1.1.5 255.255.255.0
    !
    interface FastEthernet0/1
     ip address 2.2.2.5 255.255.255.0
    !
    R5#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.5         YES manual up                    up
    FastEthernet0/1            2.2.2.5         YES manual up                    up
    !
    !
    R5#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 23 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
      Distance: (default is 120)
    !
    !
    R5#show running-config | i default
    ip default-network 2.0.0.0
    !
    !
    R5#show running-config | i ip route
    R5#
    !
    !
    R5#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
     *   2.0.0.0/24 is subnetted, 1 subnets
    C       2.2.2.0 is directly connected, FastEthernet0/1

     


    R6:
    interface FastEthernet0/0
     ip address 1.1.1.6 255.255.255.0
    !
    R6#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.6         YES manual up                    up
    !
    !
    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is 1.1.1.5 to network 0.0.0.0

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    R*   0.0.0.0/0 [120/1] via 1.1.1.5, 00:00:19, FastEthernet0/0
    !
    !R6#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 19 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
        1.1.1.5              120      00:00:05
      Distance: (default is 120)

    Note there is no static route configured becasue of the "ip default-network" command.

     

    For EIGRP, the network configured as "default-network" needs to either be learned through EIGRP, or if it is locally attached (connected or static) it needs to be advertised into EIGRP. Once you do this, EIGRP will flag this network as candidate default and advertise it through EIGRP with candidate default flag (EIGRP understands this flag). So on the neighbor routers, there will be no 0.0.0.0/0 route as in RIP. For EIGRP to announce the configured network as candidate-default,in comparison with RIP, it needs to have in EIGRP a PERFECT match on the classful network (so it needs to have 2.0.0.0/8); in RIP it was sufficient to have a subnet of it.

    R5:
    interface FastEthernet0/1
     ip address 2.0.0.5 255.0.0.0
    !
    R5#show running-config | i default-network
    ip default-network 2.0.0.0
    !
    R5#show running-config | i ip route
    R5#
    !
    !
    R5#show ip protocols
    Routing Protocol is "eigrp 10"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Default networks flagged in outgoing updates
      Default networks accepted from incoming updates
      EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
      EIGRP maximum hopcount 100
      EIGRP maximum metric variance 1
      Redistributing: eigrp 10
      EIGRP NSF-aware route hold timer is 240s
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.1.1.5/32
        2.0.0.5/32
      Routing Information Sources:
        Gateway         Distance      Last Update
        1.1.1.6               90      00:07:45
      Distance: internal 90 external 170
    !
    R5#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    C*   2.0.0.0/8 is directly connected, FastEthernet0/1

     

    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is 1.1.1.5 to network 2.0.0.0

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    D*   2.0.0.0/8 [90/307200] via 1.1.1.5, 00:07:45, FastEthernet0/0

    Now we change the prefix on R5, candidate default flag no longer advertised:

    R5:
    interface FastEthernet0/1
     ip address 2.2.2.5 255.255.255.0
    !
    R5(config)#router eigrp 10
    R5(config-router)#no  network 2.0.0.5 0.0.0.0
    R5(config-router)#network 2.2.2.5 0.0.0.0


    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
         2.0.0.0/24 is subnetted, 1 subnets
    D       2.2.2.0 [90/307200] via 1.1.1.5, 00:00:18, FastEthernet0/0

    Also, in the end, if we have candidate-default route (shows up with * in "show ip route"), it does not mean that it is the default route; we can have in the routing table multiple "candidate default" candidates as well as a "0.0.0.0/0" entry, so we'll have a regular selection, as for any other prefix, on who wins the default route election.

    Good luck with your studies!

  • Hi all,

      I remember i also had a fight with this feature. :) So, ip default-network works only for DV protocols (RIP,IGRP,EIGRP); for all, the network advertised with command "ip default-network" needs to be classfull(ip default-network 2.0.0.0 and NOT ip default-network 2.2.2.0).

    For RIP, the network that you flag as candidate for default route, does not need to be advertised through RIP (it can be but it is not required). As RIP does not understand the "candidate default" flag in RIP updates, the router on which "ip default-network" is configured advertised a 0.0.0.0/0 route out on its RIP enabled interfaces. The requirement to do this, is to have at least one subnet from the major prefix in its routing table(note in the bellow example i have 2.2.2.0/24 on my interface, not 2.0.0.0/8).

    For EIGRP, the network configured as "default-network" needs to either be learned through EIGRP, or if it is locally attached (connected or static) it needs to be advertised into EIGRP. Once you do this, EIGRP will flag this network as candidate default and advertise it through EIGRP with candidate default flag (EIGRP understands this flag). So on the neighbor routers, there will be no 0.0.0.0/0 route as in RIP. For EIGRP to announce the configured network as candidate-default,in comparison with RIP, it needs to have in EIGRP a PERFECT match on the classful network (so it needs to have 2.0.0.0/8); in RIP it was sufficient to have a subnet of it.

    Also, in the end, if we have candidate-default route (shows up with * in "show ip route"), it does not mean that it is the default route; we can have in the routing table multiple "candidate default" candidates as well as a "0.0.0.0/0" entry, so we'll have a regular selection, as for any other prefix, on who wins the default route election. The following CCO document, explains in some detail this functionality:
    http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml

    It seems i cannot write long posts, in following reply i will add configuration used.


    Good luck with your studies!

  • Bellow RIP test plan:

    R5:
    interface FastEthernet0/0
     ip address 1.1.1.5 255.255.255.0
    !
    interface FastEthernet0/1
     ip address 2.2.2.5 255.255.255.0
    !
    R5#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.5         YES manual up                    up
    FastEthernet0/1            2.2.2.5         YES manual up                    up
    !
    !
    R5#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 23 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
      Distance: (default is 120)
    !
    !
    R5#show running-config | i default
    ip default-network 2.0.0.0
    !
    !
    R5#show running-config | i ip route
    R5#
    !
    !
    R5#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
     *   2.0.0.0/24 is subnetted, 1 subnets
    C       2.2.2.0 is directly connected, FastEthernet0/1

     


    R6:
    interface FastEthernet0/0
     ip address 1.1.1.6 255.255.255.0
    !
    R6#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.6         YES manual up                    up
    !
    !
    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is 1.1.1.5 to network 0.0.0.0

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    R*   0.0.0.0/0 [120/1] via 1.1.1.5, 00:00:19, FastEthernet0/0
    !
    !R6#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 19 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
        1.1.1.5              120      00:00:05
      Distance: (default is 120)


    Note there is no static route configured becasue of the "ip default-network" command.

  • Bellow EIGRP test plan (RIP was removed):

    R5:
    interface FastEthernet0/1
     ip address 2.0.0.5 255.0.0.0
    !
    R5#show running-config | i default-network
    ip default-network 2.0.0.0
    !
    R5#show running-config | i ip route
    R5#
    !
    !
    R5#show ip protocols
    Routing Protocol is "eigrp 10"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Default networks flagged in outgoing updates
      Default networks accepted from incoming updates
      EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
      EIGRP maximum hopcount 100
      EIGRP maximum metric variance 1
      Redistributing: eigrp 10
      EIGRP NSF-aware route hold timer is 240s
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.1.1.5/32
        2.0.0.5/32
      Routing Information Sources:
        Gateway         Distance      Last Update
        1.1.1.6               90      00:07:45
      Distance: internal 90 external 170
    !
    R5#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    C*   2.0.0.0/8 is directly connected, FastEthernet0/1

     

    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is 1.1.1.5 to network 2.0.0.0

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    D*   2.0.0.0/8 [90/307200] via 1.1.1.5, 00:07:45, FastEthernet0/0

    Now we change the prefix on R5, candidate default flag no longer advertised:

    R5:
    interface FastEthernet0/1
     ip address 2.2.2.5 255.255.255.0
    !
    R5(config)#router eigrp 10
    R5(config-router)#no  network 2.0.0.5 0.0.0.0
    R5(config-router)#network 2.2.2.5 0.0.0.0


    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
         2.0.0.0/24 is subnetted, 1 subnets
    D       2.2.2.0 [90/307200] via 1.1.1.5, 00:00:18, FastEthernet0/0

  • Cristian, can you pos "show ip cef" and "show ip route" for 0.0.0.0 on R6?

    As far as I remember, I had problems with "D*" route records - they were present in RIB, but packets weren't routed using these routes.

  • Hi,

      I have to remake the config, however, i pinged a remote network, so default route matched.

    Good luck with your studies!

  • Bellow RIP test plan:

    R5:
    interface FastEthernet0/0
     ip address 1.1.1.5 255.255.255.0
    !
    interface FastEthernet0/1
     ip address 2.2.2.5 255.255.255.0
    !
    R5#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.5         YES manual up                    up
    FastEthernet0/1            2.2.2.5         YES manual up                    up
    !
    !
    R5#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 23 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
      Distance: (default is 120)
    !
    !
    R5#show running-config | i default
    ip default-network 2.0.0.0
    !
    !
    R5#show running-config | i ip route
    R5#
    !
    !
    R5#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
     *   2.0.0.0/24 is subnetted, 1 subnets
    C       2.2.2.0 is directly connected, FastEthernet0/1

     


    R6:
    interface FastEthernet0/0
     ip address 1.1.1.6 255.255.255.0
    !
    R6#sho ip int brief | e unas
    Interface                  IP-Address      OK? Method Status                Protocol
    FastEthernet0/0            1.1.1.6         YES manual up                    up
    !
    !
    R6#show ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
           E1 - OSPF external type 1, E2 - OSPF external type 2
           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
           ia - IS-IS inter area, * - candidate default, U - per-user static route
           o - ODR, P - periodic downloaded static route

    Gateway of last resort is 1.1.1.5 to network 0.0.0.0

         1.0.0.0/24 is subnetted, 1 subnets
    C       1.1.1.0 is directly connected, FastEthernet0/0
    R*   0.0.0.0/0 [120/1] via 1.1.1.5, 00:00:19, FastEthernet0/0
    !
    !R6#show ip protocols
    Routing Protocol is "rip"
      Outgoing update filter list for all interfaces is not set
      Incoming update filter list for all interfaces is not set
      Sending updates every 30 seconds, next due in 19 seconds
      Invalid after 180 seconds, hold down 180, flushed after 240
      Redistributing: rip
      Default version control: send version 2, receive version 2
        Interface             Send  Recv  Triggered RIP  Key-chain
        FastEthernet0/0       2     2
      Automatic network summarization is not in effect
      Maximum path: 4
      Routing for Networks:
        1.0.0.0
      Routing Information Sources:
        Gateway         Distance      Last Update
        1.1.1.5              120      00:00:05
      Distance: (default is 120)


    Note there is no static route configured becasue of the "ip default-network" command.

    I tried EXACTLY the above excelt...instead of f0/1 network 2.0.0.0...i has int s0/0/0 w/ network 54.0.0.0 as in default-network 54.0.0.0

    the serial link is a frame-relay link as per workbook 1 on r6 and the bakcbone

     

    it did not work....if i ws by my rack right now i would have labbed it up and posted the show commands...

     

    but i'll try it again....i had actually written out every combination of possible commands...and tried them and none worked

    1) classless only  default-net 54.1.1.0

    2) classful only    default-net 54.0.0.0

    30 both   default-net 54.1.1.0 and 54.0.0.0

    nothing worked...

    my layter 2 ws fine

  • Hi Toxic,

       Use "ip default-network 54.0.0.0", let me know the exact configuration you have used, also what IOS version are you running?

    Good luck with your studies!

  • Hi Toxic,

       Use "ip default-network 54.0.0.0", let me know the exact configuration you have used, also what IOS version are you running?

    Good luck with your studies!

     

    i'm away from home but now i cannot wait to try it again when i get there....i'm running12.4Tsomething....i'll post my configs and show cmd asap tomorrow

    as always...your help is appreciated!

     

  • ok so here we go****

     

    topology  BackBone------------Frame-Relay <net 54.0.0.0/24>------------s0/0/0(R6)f0/0.146------155.1.146.0/24-------------f0/0(R1)

    ---------------------------------------------------------------------------------------------------------

    IOS used    

     

    Rack1R6#sh ver | i IOS

    Cisco IOS Software, 1841 Software (C1841-ADVENTERPRISEK9-M), Version 12.4(24)T2, RELEASE SOFTWARE (fc2)

    Rack1R1#sh ver | i IOS

     

    Cisco IOS Software, C2600 Software (C2600-ADVENTERPRISEK9-M), Version 12.4(19), RELEASE SOFTWARE (fc1)

    --------------------------------------------------------------------------------------------------------------


    R6 Interfaces,Rip config and routing table and default net cmd



    Rack1R6#sh ip int brief

    Interface                  IP-Address      OK? Method Status                Protocol

    FastEthernet0/0            unassigned      YES unset  up                    up  

    FastEthernet0/0.67         155.1.67.6      YES manual administratively down down

    FastEthernet0/0.146        155.1.146.6     YES manual up                    up  

    FastEthernet0/1            unassigned      YES unset  administratively down down

    Serial0/0/0                54.1.1.6           YES manual up                    up  

    Loopback0                  150.1.6.6         YES manual up                    up 




                                   ----------------------------------


    Rack1R6#sh run | s rip

    router rip

     version 2

     network 150.1.0.0

     network 155.1.0.0

     no auto-summary


                                      ---------------------------------



    Rack1R6#sip | b Gate

    Gateway of last resort is not set


         155.1.0.0/24 is subnetted, 1 subnets

    C       155.1.146.0 is directly connected, FastEthernet0/0.146

         54.0.0.0/24 is subnetted, 1 subnets

    C       54.1.1.0 is directly connected, Serial0/0/0

         150.1.0.0/24 is subnetted, 2 subnets

    C       150.1.6.0 is directly connected, Loopback0

    R       150.1.1.0 [120/1] via 155.1.146.1, 00:00:27, FastEthernet0/0.146       <<<<R1 loopback..does not concern us/L2 working


                                         --------------------------------




    Rack1R6#sh run | i default

    ip default-network 54.0.0.0



    -------------------------------------------------------------------------------------------------------

    R1  Rip config, interfaces and RIB



    Rack1R1#sh run | s rip

    router rip

     version 2

     network 150.1.0.0

     network 155.1.0.0

     no auto-summary





                                 -------------------


    Rack1R1#show ip int brief | i up

    FastEthernet0/0            155.1.146.1     YES manual up                    up  

    Loopback0                  150.1.1.1       YES manual up                    up  



                                --------------------





    Rack1R1(config)#do sip | b Gate

    Gateway of last resort is not set


         155.1.0.0/24 is subnetted, 1 subnets

    C       155.1.146.0 is directly connected, FastEthernet0/0

         150.1.0.0/24 is subnetted, 2 subnets

    R       150.1.6.0 [120/1] via 155.1.146.6, 00:00:17, FastEthernet0/0    

    C       150.1.1.0 is directly connected, Loopback0



                              ---------------------------------------------


    as you can see...nothing












     

     

     

     

     

     

     

     


    EDIT************************


    Rack1R6#show ip pro

    % Ambiguous command:  "show ip pro"

    Rack1R6#show ip protocol

    Routing Protocol is "rip"

      Outgoing update filter list for all interfaces is not set

      Incoming update filter list for all interfaces is not set

      Sending updates every 30 seconds, next due in 22 seconds

      Invalid after 180 seconds, hold down 180, flushed after 240

      Redistributing: rip

      Default version control: send version 2, receive version 2

        Interface             Send  Recv  Triggered RIP  Key-chain

        FastEthernet0/0.67    2     2

        FastEthernet0/0.146   2     2

        Loopback0             2     2

      Automatic network summarization is not in effect

      Maximum path: 4

      Routing for Networks:

        150.1.0.0

        155.1.0.0

      Routing Information Sources:

        Gateway         Distance      Last Update

        155.1.146.1          120      00:00:08

        155.1.67.7           120      00:14:43

      Distance: (default is 120)

    ----------------------------------------------
     


    Rack1R1(config)#do sh ip protocol

    Routing Protocol is "rip"

      Outgoing update filter list for all interfaces is not set

      Incoming update filter list for all interfaces is not set

      Sending updates every 30 seconds, next due in 25 seconds

      Invalid after 180 seconds, hold down 180, flushed after 240

      Redistributing: rip

      Default version control: send version 2, receive version 2

        Interface             Send  Recv  Triggered RIP  Key-chain

        FastEthernet0/0       2     2

        Serial0/0.1           2     2

        Serial0/1             2     2

        Loopback0             2     2

      Automatic network summarization is not in effect

      Maximum path: 4

      Routing for Networks:

        150.1.0.0

        155.1.0.0

      Routing Information Sources:

        Gateway         Distance      Last Update

        155.1.146.6          120      00:00:06

        155.1.13.3           120      00:15:06

        155.1.0.5            120      00:15:01

      Distance: (default is 120)

     

     

  • ToxicAvenginator - It works on my GNS3 network. I wonder if it could
    be because of HW (C1841) you use.

    r2#sh ver | i IOS
    Cisco IOS Software, 2600 Software (C2691-ADVENTERPRISEK9-M), Version
    12.4(15)T13, RELEASE SOFTWARE (fc3)

    Andrius
  • Hi Toxic,

        Can you try and switch the roles of the two boxes: so originate the default from the 12.4 mainline, not from the T version. Maybe things have changed in T release.

    Good luck with your studies!

  • Hi Toxic,

        Can you try and switch the roles of the two boxes: so originate the default from the 12.4 mainline, not from the T version. Maybe things have changed in T release.

    Good luck with your studies!

     

    i shall...lets try it******

    ROUTER 1 configs

     

     

    Rack1R1#sh ip int brief | i up

    FastEthernet0/0            155.1.146.1     YES manual up                    up  

    Loopback0                  150.1.1.1       YES manual up                    up       <going to use loopback this timeto keep RIB small>

                         ------------------------------------

     

    Rack1R1#sh run | s rip

    router rip

     version 2

     network 150.1.0.0

     network 155.1.0.0

     no auto-summary 

                        -------------------------------------------------------

    Rack1R1#sh run | s default

     

    ip default-network 150.1.0.0 

                         ------------------------------------------------------

     


    Gateway of last resort is not set


         155.1.0.0/24 is subnetted, 1 subnets

    C       155.1.146.0 is directly connected, FastEthernet0/0

     *   150.1.0.0/24 is subnetted, 2 subnets

    R       150.1.6.0 [120/1] via 155.1.146.6, 00:00:11, FastEthernet0/0

    C       150.1.1.0 is directly connected, Loopback0




    WHAT!!!!!!!!! IT WORKS!!!!!!!!!!!!!!!!!!!!

     

     

    -----------------------------------------------------------------------------------------------

     

     

     

     

     

     

     

     

     

     

     

    -----------------------------

    ROUTER 6 CMDS 

     

     

    Rack1R6#sh ip int brief | i up

    FastEthernet0/0            unassigned      YES unset  up                    up  

    FastEthernet0/0.146        155.1.146.6     YES manual up                    up  

    Loopback0                  150.1.6.6       YES manual up                    up  

    Loopback6                  166.1.1.1       YES manual up                    up  

                            ------------------------------------------

     

     

     

    Rack1R6#sh run | s rip

    router rip

     version 2

     network 54.0.0.0

     network 150.1.0.0

     network 155.1.0.0

     no auto-summary

     

    -------------------------------------------------------------------------------------

     

    Rack1R6#sip

    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

           D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

           N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

           E1 - OSPF external type 1, E2 - OSPF external type 2

           i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

           ia - IS-IS inter area, * - candidate default, U - per-user static route

           o - ODR, P - periodic downloaded static route

     

    Gateway of last resort is 155.1.146.1 to network 0.0.0.0

     

         155.1.0.0/24 is subnetted, 1 subnets

    C       155.1.146.0 is directly connected, FastEthernet0/0.146

         166.1.0.0/24 is subnetted, 1 subnets

    C       166.1.1.0 is directly connected, Loopback6

         150.1.0.0/24 is subnetted, 2 subnets

    C       150.1.6.0 is directly connected, Loopback0

    R       150.1.1.0 [120/1] via 155.1.146.1, 00:00:12, FastEthernet0/0.146

    R*   0.0.0.0/0 [120/1] via 155.1.146.1, 00:00:12, FastEthernet0/0.146

     

     

     

    it WORKS!!!!! BY GEORGE IT WORKS!!!!!!!!!!!!!!!!!!!!

     

     

    --------INSTEAD OF R1 LOOPBACK I'M GOING TO USE ROUTERS 1 SERIAL0/0 (FRAME)-------------------------------

     

     

    Rack1R1#sh ip int brief | ex una

    Interface                  IP-Address      OK? Method Status                Protocol

    FastEthernet0/0            155.1.146.1     YES manual up                    up  

    Serial0/0.1                155.1.0.1       YES manual up                    up    <<<<using this guy as default network

    Serial0/1                  155.1.13.1      YES manual administratively down down

    Loopback0                  150.1.1.1       YES manual up                    up 

     

                    -------------------------------------------------------------------------

     

    Rack1R1(config)#ip default-network 155.1.0.0

    Rack1R1(config)#


    Rack1R1#sh run | s default

    ip default-network 155.1.0.0

                        ---------------------------------------------------------------------




     

     

     

     

     

    Gateway of last resort is not set

     

     *   155.1.0.0/24 is subnetted, 8 subnets

    C       155.1.146.0 is directly connected, FastEthernet0/0

    R       155.1.10.0 [120/3] via 155.1.0.5, 00:00:12, Serial0/0.1

    R       155.1.8.0 [120/2] via 155.1.0.5, 00:00:12, Serial0/0.1

    C*      155.1.0.0 is directly connected, Serial0/0.1

    R       155.1.5.0 [120/1] via 155.1.0.5, 00:00:12, Serial0/0.1

    R       155.1.58.0 [120/1] via 155.1.0.5, 00:00:12, Serial0/0.1

    R       155.1.45.0 [120/1] via 155.1.0.5, 00:00:12, Serial0/0.1

    R       155.1.108.0 [120/2] via 155.1.0.5, 00:00:13, Serial0/0.1

         150.1.0.0/24 is subnetted, 5 subnets

    R       150.1.6.0 [120/1] via 155.1.146.6, 00:00:10, FastEthernet0/0

    R       150.1.5.0 [120/1] via 155.1.0.5, 00:00:13, Serial0/0.1

    C       150.1.1.0 is directly connected, Loopback0

    R       150.1.10.0 [120/3] via 155.1.0.5, 00:00:16, Serial0/0.1

    R       150.1.8.0 [120/2] via 155.1.0.5, 00:00:16, Serial0/0.1

    -----------------------------------------------------------------

     

    on ROUTER 6

     

     

    Rack1R6#show ip route | i 0.0.0.0

    Gateway of last resort is 155.1.146.1 to network 0.0.0.0

    R*   0.0.0.0/0 [120/1] via 155.1.146.1, 00:00:03, FastEthernet0/0.146

     

     

     

     

    it works AGAIN!!!!

    i dont know what to say Christian!!!  i'm surprised and baffeled>> 

     

     

     

  • Hi Toxic,

       So it seems things are different in the T version, i will test my own T version(s) and see what the results are, share it with you.

    Good luck with your studies!

  • you know i had previously tried it out another router..router 4..turns out..i never thought it ws the IOS that ws making the difference..i thought it ws the router


    Rack1R4#sh ver | i IOS

    Cisco IOS Software, 1841 Software (C1841-ADVENTERPRISEK9-M), Version 12.4(24)T2, RELEASE SOFTWARE (fc2)

     

     

    Lesson learned>>everylittle bit i learn is a step in the right direction

     

    Thankyou again :-)

  • Hi Toxic,

      With EIGRP it works regardless of IOS version, with RIP i've tested with both 12.4 mainline and 12.4T and it was functional, however in your case it seems it is not with 12.4T version.

    Good luck with your studies!

  • Hi Toxic,

      With EIGRP it works regardless of IOS version, with RIP i've tested with both 12.4 mainline and 12.4T and it was functional, however in your case it seems it is not with 12.4T version.

    Good luck with your studies!

    Thankyou> appreciate you taking the time to sort this out for us.

     

    I'll keep en eye out for other wierd behavior from R6

     

     

  • For EIGRP, the network configured as "default-network" needs to either be learned through EIGRP, or if it is locally attached (connected or static) it needs to be advertised into EIGRP.

     

    i have the above statement in bold in my notes...BUT...i have tried and tried and pulled my hair out and then tried again....

     

    it DOES NOT WORK....i give up...i'm done with this stupid topic...i know how to configure it...i know how cisco says to configure it and how it SHOULD work but it does not....

     

    i went thru this schpiel a SECOND time after i made the original post...it DOES NOT WORK...either that or my IOS is corrupt...

     

    if i get this on my lab...i'll configure it....and move on without testing it....

     

    thats all

     

    Tox

  • it was supposed to work with T lines, do u checked with any T?

  • it was supposed to work with T lines, do u checked with any T?

    i'm running 12.4T

     

    i just powered down my lab otherwise i'd have posted the exact version of what i'm running...

     

    as i said before...there r 2 things that i have come to HATE while prepping for my lab

    1) the default-network command

    2) PfR because for the time i spent getting really good at it...

    a)i know absolutely NOONE is ever ever ever going to use it in the real world

    b) when assigning active probes i had days and days worth of problems to get them to work...till one day i left my lab to go to lunch and came back to find them working for gawd knows what reason :(

  • Do u ever seen oer/pfr in any real network? For me no way.

  • I have never seen this oer/pfr in any running network. Do you come across this technology in real world?

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