Multicast ping on a Nexus device

When pinging a multicast address from a Cisco Nexus device, you may receive the following error message:

ping: either multicast replicate flag or source interface needs to be specified

Nexus devices, unlike IOS devices, require additional parameters when pinging multicast addresses. These parameters include:

  • The replicate flag is an additional TLV option that is added by Nexus devices in order to specify if the ping echo request should be replicated upon exiting an interface of the device.
  • Specifying the exit interface will enable the device to use the default replicate status of that exit interface to determine if the ping echo request should be replicated.

In order to successfully ping a multicast address, one of the following must be done:

  • Using extended ping commands, specify the exit interface to be used.
  • Alternatively, using extended ping commands, choose all the default parameters. It seems that extended ping with all the defaults will successfully ping a multicast address.
  • Use the ping multicast command if it is available.

Links:

https://community.cisco.com/t5/switching/multicast-commands/td-p/1751366

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3548/sw/cmd_ref/503_A1/fundamental/3548_cmd_ref_fund/3k_cmd_ref_fund_cmds.html#pgfId-1029205

https://learningnetwork.cisco.com/s/question/0D53i00000Ksrim/multicast-routing-on-nxos-within-vrf

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/command/reference/fund/n5k-fund-cr/n5k-fund_cmds_p.html#pgfId-1248304

https://datatracker.ietf.org/doc/rfc6450/