PIM Dense-mode Lab

Hi All,

 

I was wondering if someone could explain to me why I am seeing so many PIM Neighbors on all of my routers in this lab topology.

Check out R4 for example

 

R4#sh ip pim neighbor
PIM Neighbor Table
Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
      S - State Refresh Capable
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode
150.1.56.5        FastEthernet0/0          00:17:47/00:01:41 v2    1 / S
150.1.15.5        FastEthernet0/0          00:57:02/00:01:41 v2    1 / S
150.1.56.6        FastEthernet0/0          00:57:02/00:01:42 v2    1 / DR S
150.1.15.1        FastEthernet0/0          00:57:02/00:01:40 v2    1 / S
150.1.24.2        FastEthernet0/0          00:28:34/00:01:42 v2    1 / S
150.1.45.5        Serial0/0.1              00:18:11/00:01:17 v2    1 / S
R4#

Why are so many neighbors showoing up? I show only see R2 150.1.24.2 and R5 150.1.45.5 as neighbors since they are the only direct connections?

 

Any help is appreciated.

 

 

 

 

Comments

  • No ideas? I also tried the same with Sparse-mode and I am seeing the same amount of neighbors.

  • Problem is that you have not setup your Layer 2 as per diagram.  You have to put interfaces into appropriate vlans so they will communicate only with the neighbor on the same subnet. I was just able to replicate your problem ... see below:

    R4#sh ip pim neigh
    PIM Neighbor Table
    Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
          S - State Refresh Capable
    Neighbor          Interface                Uptime/Expires    Ver   DR
    Address                                                            Prio/Mode
    150.1.15.5        FastEthernet0/0          00:01:56/00:01:18 v2    1 / S
    150.1.15.1        FastEthernet0/0          00:01:56/00:01:17 v2    1 / S
    150.1.56.5        FastEthernet0/0          00:01:56/00:01:18 v2    1 / S
    150.1.56.6        FastEthernet0/0          00:01:56/00:01:17 v2    1 / DR S
    150.1.24.2        FastEthernet0/0          02:01:04/00:01:17 v2    1 / S
    150.1.45.5        Serial0/0.1              02:00:56/00:01:29 v2    1 / S
    R4#

    all i did is placed all interface into vlan 1.

    1.  Need to makde sure trunking is working between all switches.

    2. Assign interface into appropriate VLAN's

    R1_f0/0 -> SW1_f1/0 (VLAN15) R5_F0/1 -> SW3_f0/5

    SW1#sh vla brie | ex uns

    VLAN Name                             Status    Ports
    ---- -------------------------------- --------- -------------------------------
    1    default                          active    Fa0/2, Fa0/4, Fa0/6, Fa0/7
                                                    Fa0/8, Fa0/9, Fa0/10, Fa0/11
                                                    Fa0/12, Fa0/22, Fa0/23, Fa0/24
                                                    Gi0/1, Gi0/2
    15   VLAN0015                         active    Fa0/1
    56   VLAN0056                         active    Fa0/5
    SW1#
    ##################################################################################

    SW2#sh vlan brie | ex uns

    VLAN Name                             Status    Ports
    ---- -------------------------------- --------- -------------------------------
    1    default                          active    Fa0/1, Fa0/3, Fa0/5, Fa0/7
                                                    Fa0/8, Fa0/9, Fa0/10, Fa0/11
                                                    Fa0/12, Fa0/16, Fa0/17, Fa0/18
                                                    Fa0/19, Fa0/20, Fa0/21, Fa0/22
                                                    Fa0/23, Fa0/24, Gi0/1, Gi0/2
    24   VLAN0024                         active    Fa0/2, Fa0/4
    56   VLAN0056                         active    Fa0/6

    ##################################################################################

    SW3#sh vlan bri | ex uns

    VLAN Name                             Status    Ports
    ---- -------------------------------- --------- -------------------------------
    1    default                          active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                                    Fa0/6, Fa0/7, Fa0/8, Fa0/9
                                                    Fa0/10, Fa0/11, Fa0/12, Fa0/16
                                                    Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                                    Fa0/21, Fa0/22, Fa0/23, Fa0/24
                                                    Gi0/1, Gi0/2
    15   VLAN0015                         active    Fa0/5
    ##################################################################################

    R4#sh ip pim neigh
    PIM Neighbor Table
    Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
          S - State Refresh Capable
    Neighbor          Interface                Uptime/Expires    Ver   DR
    Address                                                            Prio/Mode
    150.1.24.2        FastEthernet0/0          02:13:11/00:01:30 v2    1 / S
    150.1.45.5        Serial0/0.1              02:13:03/00:01:41 v2    1 / S

    R4#

    Note: all my router use fast ethernet ports but the line above is the example...

    Dmitriy

     

     

     

Sign In or Register to comment.