[All About Switches] When a Switch Is Dual-homed to ME60s and Has PIM Configured, Unidirectional PIM Communication Occurs, Causing Two DRs

Latest reply: Mar 9, 2018 00:32:08 949 1 0 0

Involved Products and Versions

All versions of modular switches

Networking

In Figure 1-1, ME60-1 and ME60-2 are connected to the Switch through Eth-Trunk3 and Eth-Trunk2 respectively. Multicast subinterfaces of ME60-1 and ME60-2 are Eth-Trunk3.50 and Eth-Trunk2.50 respectively, and PIM is configured on ME60-1 and ME60-2.

Figure 1-1 Networking diagram

20180308102140394001.png

 

Symptom

Both ME60-1 and ME60-2 are DRs, and PIM DR election fails. ME60-1 and ME60-2 forward multicast traffic to the switch separately.

Cause Analysis

Eth-Trunk3 member interface XGE10/0/1 of the Switch has the multicast-suppression packets 0 command configuration. This configuration enables XGE10/0/1 to discard PIM packets.

Procedure

                          Step 1     Run the display pim interface command on ME60-1 and ME60-2 to view PIM information on interfaces. The command output shows that DR priorities of both ME60-1 and ME60-2 are 1 and their DR addresses are local. This indicates that the Switch does not forward PIM packets normally.

<ME60-1> display pim interface Eth-Trunk 3.50
VPN-Instance: public net
Interface     State NbrCnt HelloInt DR-Pri DR-Address
Eth-Trunk3.50 up    0      30       1      10.194.163.17 (local)

<ME60-2> display pim interface Eth-Trunk 2.50
VPN-Instance: public net
Interface     State NbrCnt HelloInt DR-Pri DR-Address
Eth-Trunk2.50 up    1      30       1      10.194.163.18 (local)

                          Step 2     On the Switch, collect traffic statistics of Eth-Trunk2 and Eth-Trunk3, and then run the display traffic policy statistics interface interface-type interface-number inbound command to view the traffic volume. The command output shows that the Switch receives PIM Hello packet of ME60-2 but does not forward the packet through Eth-Trunk3.

#
acl number 3000
 rule 5 permit ip destination 224.0.0.13 0
#
traffic classifier test
 if-match acl 3000
#
traffic behavior test
 statistic enable
#
traffic policy test
 classifier test behavior test
#
interface Eth-Trunk2
 traffic-policy test inbound 
 traffic-policy test outbound 
#
interface Eth-Trunk3
 traffic-policy test inbound 
 traffic-policy test outbound

                          Step 3     Check the configuration of Eth-Trunk3 on the Switch, finding that Eth-Trunk3 member interface XGE10/0/1 has the multicast-suppression packets 0 command configuration. This configuration enables XGE10/0/1 to discard PIM packets. After this command configuration is deleted, this problem is solved.

----End

  • x
  • convention:

gululu
Admin Created Mar 9, 2018 00:32:08 Helpful(0) Helpful(0)

thanks
  • x
  • convention:

Come on!

Reply

Reply
You need to log in to reply to the post Login | Register

Notice Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " Privacy."
If the attachment button is not available, update the Adobe Flash Player to the latest version!
Login and enjoy all the member benefits

Login and enjoy all the member benefits

Login